Methimazole

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 121 min read
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Methimazole ( Metirox 5 and 10 mg) is a member of the class of imidazoles that it imidazole-2-thione in which a methyl group replaces the hydrogen that is attached to nitrogen. It has a role as an antithyroid drug. Methimazole is a thionamide antithyroid agent that inhibits the synthesis...

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Article Summary

Methimazole ( Metirox 5 and 10 mg) is a member of the class of imidazoles that it imidazole-2-thione in which a methyl group replaces the hydrogen that is attached to nitrogen. It has a role as an antithyroid drug. Methimazole is a thionamide antithyroid agent that inhibits the synthesis of thyroid hormones. It was first introduced as an antithyroid agent in 1949 and is now commonly used in the...

Key Takeaways

  • This article explains Mechanism of Action in simple medical language.
  • This article explains Indications in simple medical language.
  • This article explains Contraindications in simple medical language.
  • This article explains Dosages in simple medical language.
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Methimazole ( Metirox 5 and 10 mg) is a member of the class of imidazoles that it imidazole-2-thione in which a methyl group replaces the hydrogen that is attached to nitrogen. It has a role as an antithyroid drug.

Methimazole is a thionamide antithyroid agent that inhibits the synthesis of thyroid hormones. It was first introduced as an antithyroid agent in 1949 and is now commonly used in the management of hyperthyroidism, particularly in those for whom more aggressive options such as surgery or radioactive iodine therapy are inappropriate. On a weight basis, methimazole is 10 times more potent than the other major antithyroid thionamide used in North America, [propylthiouracil], and is the active metabolite of the pro-drug [carbimazole], which is an antithyroid medication used in the United Kingdom and parts of the former British Commonwealth. Traditionally, methimazole has been preferentially used over propylthiouracil due to the risk of fulminant hepatotoxicity carried by the latter, with propylthiouracil being preferred in pregnancy due to a perceived lower risk of teratogenic effects. Despite documented teratogenic effects in its published labels, the true teratogenicity of methimazole appears to be unclear and its place in therapy may change in the future.

Methimazole is a Thyroid Hormone Synthesis Inhibitor. The mechanism of action of methimazole is as a Thyroid Hormone Synthesis Inhibitor.

Mechanism of Action

Methimazole’s primary mechanism of action appears to be interference in an early step in thyroid hormone synthesis involving thyroid peroxidase (TPO), however, the exact method through which methimazole inhibits this step is unclear. TPO, along with hydrogen peroxide, normally catalyzes the conversion of iodide to iodine and then further catalyzes the incorporation of this iodine onto the 3 and/or 5 positions of the phenol rings of tyrosine residues in thyroglobulin. These thyroglobulin molecules then degrade within thyroid follicular cells to form either thyroxine (T4) or tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. Methimazole may directly inhibit TPO but has been shown in vivo to instead act as a competitive substrate for TPO, thus becoming iodinated itself and interfering with the iodination of thyroglobulin. Another proposed theory is that methimazole’s sulfur moiety may interact directly with the iron atom at the center of TPO’s heme molecule, thus inhibiting its ability to iodinate tyrosine residues. Other proposed mechanisms with weaker evidence include methimazole binding directly to thyroglobulin or direct inhibition of thyroglobulin itself.

or
Methimazole inhibits the synthesis of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin; the drug also inhibits the coupling of these iodotyrosyl residues to form iodothyronine. Although the exact mechanism(s) has not been fully elucidated, methimazole may interfere with the oxidation of iodide ion and iodotyrosyl groups. Based on limited evidence, it appears that the coupling reaction is more sensitive to antithyroid agents than the iodination reaction. Methimazole does not inhibit the action of thyroid hormones already formed and present in the thyroid gland or circulation nor does the drug interfere with the effectiveness of exogenously administered thyroid hormones.
Methimazole inhibits the synthesis of thyroid hormones resulting in an alleviation of hyperthyroidism. The onset of action occurs within 12 to 18 hours, and its duration of action is 36 to 72 hours, likely due to the concentration of methimazole and some metabolites within the thyroid gland after administration. The most serious potential side effect of methimazole therapy is agranulocytosis, and patients should be instructed to monitor for, and report, any signs or symptoms of agranulocytosis such as fever or sore throat. Other cytopenias may also occur during methimazole therapy. There also exists the potential for severe hepatic toxicity with the use of methimazole, and monitoring for signs and symptoms of hepatic dysfunction, such as jaundice, anorexia, pruritus, and elevation in liver transaminases, is prudent in patients using this therapy.

Indications

  • Antithyroid Agents especially thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism.
  • In the United States, methimazole is indicated for the treatment of thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism in patients with Graves’ disease or toxic multinodular goiter for whom thyroidectomy or radioactive iodine therapy are not appropriate treatment options. Methimazole is also indicated for the amelioration of hyperthyroid symptoms in preparation for thyroidectomy or radioactive iodine therapy. In Canada, methimazole carries the above indications and is also indicated for the medical treatment of hyperthyroidism regardless of other available treatment options.
  • Methimazole is an antithyroid medication that is now considered the first-line agent for medical therapy of thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism and Graves disease. Methimazole has been linked to serum aminotransferase elevations during therapy as well as to a clinically apparent, idiosyncratic liver injury that is typically cholestatic and self-limited in course.
  • A prospective randomized control study of combination therapy with low-dose methimazole and a cholesterol absorption inhibitor as for the initial treatment of childhood-onset Graves disease
  • Methimazole /is/ indicated in the treatment of thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism, including prior to surgery or radiotherapy, and as adjunct in the treatment of thyrotoxicosis or thyroid storm. Propylthiouracil may be preferred over methimazole for use in thyroid storm, since propylthiouracil inhibits peripheral conversion of thyroxine (T4) to triiodothyronine (T3)
  • Graves’ Disease
  • thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">Hyperthyroidism
  • Toxic multinodular goiter
  • Thiamazole, also known as methimazole, is a medication used to treat thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism.[rx] This includes Graves disease, toxic multinodular goiter, and thyrotoxic crisis.[rx] It is taken by mouth.[rx] Full effects may take a few weeks to occur.[rx]

Contraindications

  • Methimazole is contraindicated if there is hypersensitivity to the drug or any of its components.
  • It is relatively contraindicated during pregnancy.
  • Hypersensitivity to the active substance or any product excipients

Dosages

Strengths: 5 mg; 10 mg; 15 mg; 20 mg

thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">Hyperthyroidism

Initial dose:

  • Mild thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।" data-rx-term="hyperthyroidism" data-rx-definition="Hyperthyroidism means the thyroid gland makes too much hormone. সহজ বাংলা: থাইরয়েড হরমোন বেশি।">hyperthyroidism: 15 mg orally per day
  • Moderately severe hyperthyroidism: 30 to 40 mg orally per day
  • Severe hyperthyroidism: 60 mg orally per day

Maintenance dose:

  • 5 to 15 mg orally per day. Daily doses are usually given in 3 divided doses at approximately 8 hour intervals
  • For the treatment of Graves’ disease with hyperthyroidism or toxic multinodular goiter in whom surgery or radioactive iodine therapy is not an appropriate treatment option.
  • To ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy.

Pediatric Dose for Hyperthyroidism

  • Initial dose: 0.4 mg/kg orally per day
  • Maintenance dose: 0.2 mg/kg orally per day (approximately half the initial dose)
  • Daily doses are usually given in 3 divided doses at approximately 8 hour intervals

or

Methimazole is available as oral tablets in 5 mg and 10 mg strengths. The starting dose is between 20 to 40 mg per day, depending upon the severity of the disease.

  • The daily dose gets divided into three doses every 8 hours.
  • As per the “titration regimen,” the high starting dose is then tapered after 4 to 8 weeks. A maintenance dose of 5 to 20 mg follows after almost 4 to 6 months of therapy, which continues for an extra 12 to 18 months.
  • As per the “block–replace regimen,” a high dose of antithyroid drugs is maintained, but with levothyroxine therapy to maintain a euthyroid state. It has the added benefit of needing fewer thyroid function tests (TFTs) for monitoring but with a slightly increased side effect frequency.

The treatment of thyroid storm includes a starting dose of 60 to 80 mg/day orally until achieving control, also given at 8-hour intervals. Adjust the subsequent doses and duration of treatment as per patient response.

Methimazole has a narrow therapeutic window. Therefore it is essential to note the maximum allowed dosage.

  • Adults:40 mg/day orally; up to 60 mg/day in severe disease.
  • Geriatric:40 mg/day orally; up to 60 mg/day in severe disease.
  • Adolescents: Maintenance doses rarely exceed 30 mg/day orally; 1 mg/kg/day orally in severe hyperthyroidism. Patients who have attained full growth doses may approach adult dosing.
  • Children: Maintenance doses rarely exceed 30 mg/day orally or 1 mg/kg/day if severe hyperthyroidism.
  • Infants:1 mg/kg/day if severe hyperthyroidism.
  • Pregnant Women: It is classified as Pregnancy Category D medicine. Fetal harm is reported when methimazole is administered to a pregnant woman. If the woman becomes pregnant while taking methimazole or when methimazole is used during pregnancy, the patient should be counseled on the potential risk to the fetus. In addition, prescribe alternative treatments for hyperthyr

Administration advice:

  • Take orally in equally divided doses at approximately 8-hour intervals

General:

  • Patients treated with this drug should be under close surveillance due to the potential for serious adverse effects.
  • Avoid use during the first trimester of pregnancy due to reports of fetal abnormalities; after the first trimester it may be preferable to switch to methimazole due to hepatotoxicity of propylthiouracil.

Monitoring:

  • Routine monitoring of TSH and free T4 levels is necessary to avoid under or over-treatment
  • Consider monitoring prothrombin time if there are concerns of bleeding; prothrombin time should be monitored before surgical procedures
  • Obtain complete blood counts if there are signs and symptoms of agranulocytosis
  • Perform liver function testing if there are any symptoms of hepatic dysfunction

Patient dosage advice:

  • Patients should understand the importance of contacting their healthcare provider promptly if they experience any signs or symptoms of liver dysfunction, low blood counts, bleeding, or vasculitis.
  • Women should be instructed to speak to their healthcare provider if they are pregnant or plan to become pregnant.

Side Effects

The Most Common

  • skin rash
  • itching
  • abnormal hair loss
  • upset stomach
  • vomiting
  • loss of taste
  • abnormal sensations (tingling, prickling, burning, tightness, and pulling)
  • swelling
  • joint and muscle pain
  • drowsiness
  • dizziness
  • decreased white blood cells
  • decreased platelets
  • sore throat
  • fever
  • headache
  • chills
  • unusual bleeding or bruising
  • right-sided abdominal pain with decreased appetite
  • yellowing of the skin or eyes
  • skin eruptions

More Common

Other known side effects include:

  • skin rash
  • itching
  • abnormal hair loss
  • upset stomach
  • vomiting
  • loss of taste
  • abnormal sensations (tingling, prickling, burning, tightness, and pulling)
  • swelling
  • joint and muscle pain
  • drowsiness
  • dizziness
  • decreased platelet count (thrombocytopenia)
  • aplasia cutis congenital (prenatal exposure)
  • thyroid gland enlargement (prenatal exposure)
  • choanal atresia (prenatal exposure during the first trimester of pregnancy)
  • acute pancreatitis

Rare

Serious adverse effects:

Agranulocytosis

  • The cut-off criterion for it is an absolute granulocyte count of less than 500 per mL.
  • It most frequently occurs in the first three months of starting therapy but can occur even after a year or more of exposure or during repeated exposures when treating a relapse.
  • Regular monitoring of granulocyte count is considered useless by most experts.
  • Fever and sore throat are the most common presenting features of agranulocytosis. Therefore, all patients should get verbal and written instruction regarding the importance of getting an urgent white cell count if these symptoms arise to confirm the absence of this complication for continued antithyroid drug therapy.

  • Stop methimazole if the count is less than 1000 per ml. Treat fever or any apparent infections with intravenous antibiotics.

    • IV granulocyte colony-stimulating factor is known to reduce the length of hospitalization and recovery time.
  • Propylthiouracil (PTU) and methimazole have cross-reactivity for agranulocytosis, so avoid using the former in such patients.

Hepatotoxicity 

  • The hepatic toxicity of methimazole is more of a cholestatic process than allergic hepatitis seen in propylthiouracil and recovers slowly after discontinuing the drug.

Teratogenicity 

  • Methimazole can cross the placental membrane readily due to its insignificant protein binding. During the organogenesis phase, it causes immense fetal adverse effects, especially when administered in the first trimester. Possible congenital disabilities seen in infants born to mothers who received methimazole during pregnancy include goiter, cretinism, aplasia cutis, umbilical abnormalities, facial dysmorphism, esophageal atresia, craniofacial defects, and choanal atresia.
  • Propylthiouracil is the preferred antithyroid drug during pregnancy, especially for the first trimester, since the incidence of congenital anomalies is much less than methimazole. Clinicians should attempt to use the lowest effective dose, and if continuous monitoring shows the need for increased drug dosage, surgery is a consideration.

Hypothyroidism 

  • Methimazole can cause hypothyroidism. Therefore it is crucial to monitor T3 T4 levels in the serum, to adjust the dose to maintain a euthyroid state. In addition, since it crosses the placenta readily, it is capable of causing hypothyroidism and cretinism in newborns.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Drug Interactions

Pregnancy and Lactation

Pregnancy and Lactation

Use during Lactation

  • Maternal methimazole therapy does not affect thyroid function or intellectual development in breastfed infants with doses up to 20 mg daily. Taking methimazole right after nursing and waiting for 3 to 4 hours before nursing again should minimize the infant dosage. No cases of thyroid function alteration have been reported among infants exposed to methimazole via breastmilk. Some experts now recommend that methimazole should be considered the antithyroid drug of choice in nursing mothers.
  • The American Thyroid Association recommends only monitoring infants for appropriate growth and development during routine pediatric health and wellness evaluations and routine assessment of serum thyroid function in the child is not recommended. Rare idiosyncratic reactions (e.g., agranulocytosis) might occur, and the infant should be watched for signs of infection. Monitoring of the infant’s complete blood count and differential is advisable if there is a suspicion of a drug-induced blood dyscrasia.

Effects in Breastfed Infants

  • Five mothers taking methimazole 5 to 15 mg daily at 6 pm breastfed their infants during the day using expressed milk or formula at night. Thyroid Five mothers taking methimazole 5 to 15 mg daily at 6 pm breastfed their infants during the day using expressed milk or formula at night. Thyroid function test remained normal during 90 days of study and none of the infants showed any clinical signs of hypothyroidism and methimazole was undetectable (<10 mcg/L) in the infants’ serum.
  • Twelve mothers taking methimazole 5 mg daily breastfed their infants from the time of delivery. Another 17 women were given methimazole 5 mg twice daily beginning 2 to 8 months postpartum and allowed to breastfeed their infants exclusively with supplementation given to those over 6 months of age. A third group of 6 mothers took methimazole 10 mg twice daily. All infants were normal clinically and had normal thyroid function tests when measured 2 to 4 weeks after the start of therapy. (Note: this paper is apparently the full publication of a previous report in abstract form.)
  • The breastfed infants of 16 mothers who became hypothyroid during methimazole therapy were studied 5 times between birth and 12 months of age in comparison to a control group of 18 breastfed infants whose mothers did not become hypothyroid during methimazole therapy and a group of 24 infants of normal mothers. There were no differences in thyroid function tests of the infants from the 3 groups.
  • Fifty-one infants of mothers who took methimazole during pregnancy and continued during lactation with a dose of 5 mg daily and 88 infants of mothers who took the drug starting 2 to 8 months postpartum were studied. All infants had normal thyroid function tests for up to a year of maternal therapy with doses of 5 to 20 mg daily of methimazole. Fourteen children who had been breastfed as infants were compared to a control group of children whose mothers did not take methimazole. Performance on IQ tests did not differ between the two groups. Forty-two of these children were restudied after 4 years of age and found to have IQ scores equal to children under the age of 6 in a matched control group.

Effects on Lactation and Breastmilk

  • Relevant published information was not found as of the revision date.

How should this medicine be used?

Methimazole comes as a tablet and usually is taken three times a day, approximately every 8 hours, with food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand.

What special precautions should I follow?

Before taking methimazole,

  • tell your doctor and pharmacist if you are allergic to methimazol, lactose, or any other drugs.
  • tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially anticoagulants (‘blood thinners’) such as warfarin (Coumadin), beta blockers such as propranolol (Inderal), diabetes medications, digoxin (Lanoxin), theophylline (Theobid, Theo-Dur), and vitamins.
  • tell your doctor if you have or have ever had any blood disease, such as decreased white blood cells (leukopenia), decreased platelets (thrombocytopenia), or aplastic anemia, or liver disease (hepatitis, jaundice).
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. Methimazole should not be used during pregnancy or breast-feeding. If you become pregnant while taking methimazole, call your doctor immediately. Methimazole may harm the fetus.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking methimazole.

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

In case of an emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

 

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Medicine doctor / pediatrician for children / qualified clinician
Tests to discuss with doctor
  • Temperature chart and hydration assessment
  • CBC with platelet count if fever persists or dengue/other infection is possible
  • Urine test, malaria/dengue tests, chest evaluation, or blood culture only when clinically indicated
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Do I need antibiotics, or is this more likely viral?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Methimazole

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

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Frequently Asked Questions

Mechanism of Action Methimazole's primary mechanism of action appears to be interference in an early step in thyroid hormone synthesis involving thyroid peroxidase (TPO), however, the exact method through which methimazole inhibits this step is unclear. TPO, along with hydrogen peroxide, normally catalyzes the conversion of iodide to iodine and then further catalyzes the incorporation of this iodine onto the 3 and/or 5 positions of the phenol rings of tyrosine residues in thyroglobulin. These thyroglobulin molecules then degrade within thyroid follicular cells to form either thyroxine (T4) or tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. Methimazole may directly inhibit TPO but has been shown in vivo to instead act as a competitive substrate for TPO, thus becoming iodinated itself and interfering with the iodination of thyroglobulin. Another proposed theory is that methimazole’s sulfur moiety may interact directly with the iron atom at the center of TPO’s heme molecule, thus inhibiting its ability to iodinate tyrosine residues. Other proposed mechanisms with weaker evidence include methimazole binding directly to thyroglobulin or direct inhibition of thyroglobulin itself. or Methimazole inhibits the synthesis of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin; the drug also inhibits the coupling of these iodotyrosyl residues to form iodothyronine. Although the exact mechanism(s) has not been fully elucidated, methimazole may interfere with the oxidation of iodide ion and iodotyrosyl groups. Based on limited evidence, it appears that the coupling reaction is more sensitive to antithyroid agents than the iodination reaction. Methimazole does not inhibit the action of thyroid hormones already formed and present in the thyroid gland or circulation nor does the drug interfere with the effectiveness of exogenously administered thyroid hormones. Methimazole inhibits the synthesis of thyroid hormones resulting in an alleviation of hyperthyroidism. The onset of action occurs within 12 to 18 hours, and its duration of action is 36 to 72 hours, likely due to the concentration of methimazole and some metabolites within the thyroid gland after administration. The most serious potential side effect of methimazole therapy is agranulocytosis, and patients should be instructed to monitor for, and report, any signs or symptoms of agranulocytosis such as fever or sore throat. Other cytopenias may also occur during methimazole therapy. There also exists the potential for severe hepatic toxicity with the use of methimazole, and monitoring for signs and symptoms of hepatic dysfunction, such as jaundice, anorexia, pruritus, and elevation in liver transaminases, is prudent in patients using this therapy. Indications Antithyroid Agents especially hyperthyroidism. In the United States, methimazole is indicated for the treatment of hyperthyroidism in patients with Graves' disease or toxic multinodular goiter for whom thyroidectomy or radioactive iodine therapy are not appropriate treatment options. Methimazole is also indicated for the amelioration of hyperthyroid symptoms in preparation for thyroidectomy or radioactive iodine therapy. In Canada, methimazole carries the above indications and is also indicated for the medical treatment of hyperthyroidism regardless of other available treatment options. Methimazole is an antithyroid medication that is now considered the first-line agent for medical therapy of hyperthyroidism and Graves disease. Methimazole has been linked to serum aminotransferase elevations during therapy as well as to a clinically apparent, idiosyncratic liver injury that is typically cholestatic and self-limited in course. A prospective randomized control study of combination therapy with low-dose methimazole and a cholesterol absorption inhibitor as for the initial treatment of childhood-onset Graves disease Methimazole /is/ indicated in the treatment of hyperthyroidism, including prior to surgery or radiotherapy, and as adjunct in the treatment of thyrotoxicosis or thyroid storm. Propylthiouracil may be preferred over methimazole for use in thyroid storm, since propylthiouracil inhibits peripheral conversion of thyroxine (T4) to triiodothyronine (T3) Graves' Disease Hyperthyroidism Toxic multinodular goiter Thiamazole, also known as methimazole, is a medication used to treat hyperthyroidism.[rx] This includes Graves disease, toxic multinodular goiter, and thyrotoxic crisis.[rx] It is taken by mouth.[rx] Full effects may take a few weeks to occur.[rx] Contraindications Methimazole is contraindicated if there is hypersensitivity to the drug or any of its components. It is relatively contraindicated during pregnancy.[rx] Hypersensitivity to the active substance or any product excipients Dosages Strengths: 5 mg; 10 mg; 15 mg; 20 mg Hyperthyroidism Initial dose: Mild hyperthyroidism: 15 mg orally per day Moderately severe hyperthyroidism: 30 to 40 mg orally per day Severe hyperthyroidism: 60 mg orally per day Maintenance dose: 5 to 15 mg orally per day. Daily doses are usually given in 3 divided doses at approximately 8 hour intervals For the treatment of Graves' disease with hyperthyroidism or toxic multinodular goiter in whom surgery or radioactive iodine therapy is not an appropriate treatment option. To ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy. Pediatric Dose for Hyperthyroidism Initial dose: 0.4 mg/kg orally per day Maintenance dose: 0.2 mg/kg orally per day (approximately half the initial dose) Daily doses are usually given in 3 divided doses at approximately 8 hour intervals or Methimazole is available as oral tablets in 5 mg and 10 mg strengths. The starting dose is between 20 to 40 mg per day, depending upon the severity of the disease.[rx] The daily dose gets divided into three doses every 8 hours. As per the "titration regimen," the high starting dose is then tapered after 4 to 8 weeks. A maintenance dose of 5 to 20 mg follows after almost 4 to 6 months of therapy, which continues for an extra 12 to 18 months. As per the "block–replace regimen," a high dose of antithyroid drugs is maintained, but with levothyroxine therapy to maintain a euthyroid state. It has the added benefit of needing fewer thyroid function tests (TFTs) for monitoring but with a slightly increased side effect frequency.[rx][rx] The treatment of thyroid storm includes a starting dose of 60 to 80 mg/day orally until achieving control, also given at 8-hour intervals. Adjust the subsequent doses and duration of treatment as per patient response. Methimazole has a narrow therapeutic window. Therefore it is essential to note the maximum allowed dosage. Adults:40 mg/day orally; up to 60 mg/day in severe disease.[rx] Geriatric:40 mg/day orally; up to 60 mg/day in severe disease. Adolescents: Maintenance doses rarely exceed 30 mg/day orally; 1 mg/kg/day orally in severe hyperthyroidism. Patients who have attained full growth doses may approach adult dosing. Children: Maintenance doses rarely exceed 30 mg/day orally or 1 mg/kg/day if severe hyperthyroidism. Infants:1 mg/kg/day if severe hyperthyroidism. Pregnant Women: It is classified as Pregnancy Category D medicine. Fetal harm is reported when methimazole is administered to a pregnant woman. If the woman becomes pregnant while taking methimazole or when methimazole is used during pregnancy, the patient should be counseled on the potential risk to the fetus.[rx] In addition, prescribe alternative treatments for hyperthyr Administration advice: Take orally in equally divided doses at approximately 8-hour intervals General: Patients treated with this drug should be under close surveillance due to the potential for serious adverse effects. Avoid use during the first trimester of pregnancy due to reports of fetal abnormalities; after the first trimester it may be preferable to switch to methimazole due to hepatotoxicity of propylthiouracil. Monitoring: Routine monitoring of TSH and free T4 levels is necessary to avoid under or over-treatment Consider monitoring prothrombin time if there are concerns of bleeding; prothrombin time should be monitored before surgical procedures Obtain complete blood counts if there are signs and symptoms of agranulocytosis Perform liver function testing if there are any symptoms of hepatic dysfunction Patient dosage advice: Patients should understand the importance of contacting their healthcare provider promptly if they experience any signs or symptoms of liver dysfunction, low blood counts, bleeding, or vasculitis. Women should be instructed to speak to their healthcare provider if they are pregnant or plan to become pregnant. Side Effects The Most Common skin rash itching abnormal hair loss upset stomach vomiting loss of taste abnormal sensations (tingling, prickling, burning, tightness, and pulling) swelling joint and muscle pain drowsiness dizziness decreased white blood cells decreased platelets sore throat fever headache chills unusual bleeding or bruising right-sided abdominal pain with decreased appetite yellowing of the skin or eyes skin eruptions More Common Other known side effects include: skin rash itching abnormal hair loss upset stomach vomiting loss of taste abnormal sensations (tingling, prickling, burning, tightness, and pulling) swelling joint and muscle pain drowsiness dizziness decreased platelet count (thrombocytopenia) aplasia cutis congenital (prenatal exposure) thyroid gland enlargement (prenatal exposure) choanal atresia (prenatal exposure during the first trimester of pregnancy) acute pancreatitis Rare Serious adverse effects: Agranulocytosis The cut-off criterion for it is an absolute granulocyte count of less than 500 per mL. It most frequently occurs in the first three months of starting therapy but can occur even after a year or more of exposure or during repeated exposures when treating a relapse.[rx] Regular monitoring of granulocyte count is considered useless by most experts. Fever and sore throat are the most common presenting features of agranulocytosis. Therefore, all patients should get verbal and written instruction regarding the importance of getting an urgent white cell count if these symptoms arise to confirm the absence of this complication for continued antithyroid drug therapy. Stop methimazole if the count is less than 1000 per ml. Treat fever or any apparent infections with intravenous antibiotics. IV granulocyte colony-stimulating factor is known to reduce the length of hospitalization and recovery time. Propylthiouracil (PTU) and methimazole have cross-reactivity for agranulocytosis, so avoid using the former in such patients. Hepatotoxicity  The hepatic toxicity of methimazole is more of a cholestatic process than allergic hepatitis seen in propylthiouracil and recovers slowly after discontinuing the drug.[rx] Teratogenicity  Methimazole can cross the placental membrane readily due to its insignificant protein binding. During the organogenesis phase, it causes immense fetal adverse effects, especially when administered in the first trimester. Possible congenital disabilities seen in infants born to mothers who received methimazole during pregnancy include goiter, cretinism, aplasia cutis, umbilical abnormalities, facial dysmorphism, esophageal atresia, craniofacial defects, and choanal atresia.[rx][rx] Propylthiouracil is the preferred antithyroid drug during pregnancy, especially for the first trimester, since the incidence of congenital anomalies is much less than methimazole.[rx] Clinicians should attempt to use the lowest effective dose, and if continuous monitoring shows the need for increased drug dosage, surgery is a consideration. Hypothyroidism  Methimazole can cause hypothyroidism.[rx] Therefore it is crucial to monitor T3 T4 levels in the serum, to adjust the dose to maintain a euthyroid state. In addition, since it crosses the placenta readily, it is capable of causing hypothyroidism and cretinism in newborns. If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088). Drug Interactions DRUG INTERACTION 1,2-Benzodiazepine The metabolism of 1,2-Benzodiazepine can be decreased when combined with Methimazole. Abacavir Methimazole may decrease the excretion rate of Abacavir which could result in a higher serum level. Abatacept The risk or severity of adverse effects can be increased when Methimazole is combined with Abatacept. Abciximab Methimazole may increase the anticoagulant activities of Abciximab. Abemaciclib The metabolism of Abemaciclib can be decreased when combined with Methimazole. Abiraterone The metabolism of Abiraterone can be decreased when combined with Methimazole. Abrocitinib The metabolism of Abrocitinib can be decreased when combined with Methimazole. Acalabrutinib The metabolism of Acalabrutinib can be decreased when combined with Methimazole. Acebutolol The excretion of Acebutolol can be decreased when combined with Methimazole. Aceclofenac Aceclofenac may decrease the excretion rate of Methimazole which could result in a higher serum level. Acemetacin Acemetacin may decrease the excretion rate of Methimazole which could result in a higher serum level. Acenocoumarol Methimazole may decrease the anticoagulant activities of Acenocoumarol. Acetaminophen The metabolism of Acetaminophen can be decreased when combined with Methimazole. Acetazolamide Acetazolamide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Acetohexamide The therapeutic efficacy of Acetohexamide can be decreased when used in combination with Methimazole. Acetyldigitoxin The serum concentration of Acetyldigitoxin can be increased when it is combined with Methimazole. Acetylsalicylic acid The metabolism of Acetylsalicylic acid can be decreased when combined with Methimazole. Aclidinium Methimazole may decrease the excretion rate of Aclidinium which could result in a higher serum level. Acrivastine Methimazole may decrease the excretion rate of Acrivastine which could result in a higher serum level. Acyclovir The metabolism of Acyclovir can be decreased when combined with Methimazole. Adagrasib The serum concentration of Adagrasib can be increased when it is combined with Methimazole. Adalimumab The risk or severity of adverse effects can be increased when Adalimumab is combined with Methimazole. Adefovir dipivoxil Adefovir dipivoxil may decrease the excretion rate of Methimazole which could result in a higher serum level. Adenovirus type 7 va The risk or severity of infection can be increased when Adenovirus type 7 vaccine live is combined with Methimazole. Afatinib The therapeutic efficacy of Methimazole can be decreased when used in combination with Afatinib. Agomelatine The metabolism of Agomelatine can be decreased when combined with Methimazole. Albendazole The metabolism of Albendazole can be decreased when combined with Methimazole. Albutrepenonacog Methimazole may decrease the excretion rate of Albutrepenonacog alfa which could result in a higher serum level. Alclofenac Alclofenac may decrease the excretion rate of Methimazole which could result in a higher serum level. Aldesleukin The therapeutic efficacy of Methimazole can be decreased when used in combination with Aldesleukin. Alectinib The metabolism of Alectinib can be decreased when combined with Methimazole. Alefacept The risk or severity of adverse effects can be increased when Alefacept is combined with Methimazole. Alemtuzumab The risk or severity of adverse effects can be increased when Alemtuzumab is combined with Methimazole. Alfentanil The metabolism of Alfentanil can be decreased when combined with Methimazole. Alfuzosin The metabolism of Alfuzosin can be decreased when combined with Methimazole. Aliskiren The metabolism of Aliskiren can be decreased when combined with Methimazole. Allogeneic processed The therapeutic efficacy of Allogeneic processed thymus tissue can be decreased when used in combination with Methimazole. Allopurinol The risk or severity of adverse effects can be increased when Allopurinol is combined with Methimazole. Almasilate Methimazole may decrease the excretion rate of Almasilate which could result in a higher serum level. Almotriptan The metabolism of Almotriptan can be decreased when combined with Methimazole. Alogliptin The metabolism of Alogliptin can be decreased when combined with Methimazole. Alosetron The metabolism of Alosetron can be decreased when combined with Methimazole. Alpelisib The metabolism of Alpelisib can be decreased when combined with Methimazole. Alprazolam The metabolism of Alprazolam can be decreased when combined with Methimazole. Alteplase Methimazole may increase the anticoagulant activities of Alteplase. Altretamine The risk or severity of adverse effects can be increased when Altretamine is combined with Methimazole. Amantadine Methimazole may decrease the excretion rate of Amantadine which could result in a higher serum level. Ambrisentan The metabolism of Ambrisentan can be decreased when combined with Methimazole. Ambroxol The metabolism of Ambroxol can be decreased when combined with Methimazole. Amikacin Methimazole may decrease the excretion rate of Amikacin which could result in a higher serum level. Amiloride Amiloride may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Aminophenazone The metabolism of Aminophenazone can be decreased when combined with Methimazole. Aminophylline The metabolism of Aminophylline can be decreased when combined with Methimazole. Aminosalicylic acid The therapeutic efficacy of Methimazole can be decreased when used in combination with Aminosalicylic acid. Amiodarone The therapeutic efficacy of Methimazole can be decreased when used in combination with Amiodarone. Amitriptyline The metabolism of Amitriptyline can be decreased when combined with Methimazole. Amitriptylinoxide The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Amitriptylinoxide. Amlodipine The metabolism of Amlodipine can be decreased when combined with Methimazole. Ammonium chloride Methimazole may decrease the excretion rate of Ammonium chloride which could result in a higher serum level. Amoxapine The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Amoxapine. Amoxicillin Methimazole may decrease the excretion rate of Amoxicillin which could result in a higher serum level. Amphetamine The metabolism of Amphetamine can be decreased when combined with Methimazole. Amphotericin B Amphotericin B may decrease the excretion rate of Methimazole which could result in a higher serum level. Ampicillin Ampicillin may decrease the excretion rate of Methimazole which could result in a higher serum level. Amprenavir The metabolism of Amprenavir can be decreased when combined with Methimazole. Amrinone Methimazole may decrease the excretion rate of Amrinone which could result in a higher serum level. Amsacrine The risk or severity of adverse effects can be increased when Amsacrine is combined with Methimazole. Anagrelide The metabolism of Anagrelide can be decreased when combined with Methimazole. Anakinra The risk or severity of adverse effects can be increased when Anakinra is combined with Methimazole. Ancestim Methimazole may decrease the excretion rate of Ancestim which could result in a higher serum level. Ancrod Methimazole may increase the anticoagulant activities of Ancrod. Anifrolumab The risk or severity of adverse effects can be increased when Methimazole is combined with Anifrolumab. Anistreplase Methimazole may increase the anticoagulant activities of Anistreplase. Anthrax immune globulin human The therapeutic efficacy of Anthrax immune globulin human can be decreased when used in combination with Methimazole. Anthrax vaccine The therapeutic efficacy of Anthrax vaccine can be decreased when used in combination with Methimazole. Antihemophilic f Methimazole may decrease the excretion rate of Antihemophilic factor (recombinant), PEGylated which could result in a higher serum level. Antilymphocyte imm The risk or severity of adverse effects can be increased when Methimazole is combined with Antilymphocyte immunoglobulin (horse). Antipyrine The metabolism of Antipyrine can be decreased when combined with Methimazole. Antithrombin Alfa Methimazole may increase the anticoagulant activities of Antithrombin Alfa. Antithrombin III human Methimazole may increase the anticoagulant activities of Antithrombin III human. Antithymocyte The risk or severity of adverse effects can be increased when Antithymocyte immunoglobulin (rabbit) is combined with Methimazole. Antrafenine Antrafenine may decrease the excretion rate of Methimazole which could result in a higher serum level. Apalutamide The metabolism of Apalutamide can be decreased when combined with Methimazole. Apixaban The metabolism of Apixaban can be decreased when combined with Methimazole. Apomorphine The metabolism of Apomorphine can be decreased when combined with Methimazole. Apremilast The metabolism of Apremilast can be decreased when combined with Methimazole. Aprepitant The metabolism of Aprepitant can be decreased when combined with Methimazole. Ardeparin Methimazole may increase the anticoagulant activities of Ardeparin. Arformoterol The metabolism of Arformoterol can be decreased when combined with Methimazole. Argatroban Methimazole may increase the anticoagulant activities of Argatroban. Aripiprazole The metabolism of Aripiprazole can be decreased when combined with Methimazole. Aripiprazole lauroxil The metabolism of Aripiprazole lauroxil can be decreased when combined with Methimazole. Arsenic trioxide The risk or severity of adverse effects can be increased when Methimazole is combined with Arsenic trioxide. Artemether The metabolism of Artemether can be decreased when combined with Methimazole. Asciminib The serum concentration of Asciminib can be increased when it is combined with Methimazole. Asenapine The metabolism of Asenapine can be decreased when combined with Methimazole. Astemizole The metabolism of Astemizole can be decreased when combined with Methimazole. AstraZeneca COVID-19 Vaccine The therapeutic efficacy of AstraZeneca COVID-19 Vaccine can be decreased when used in combination with Methimazole. Asunaprevir The metabolism of Asunaprevir can be decreased when combined with Methimazole. Atazanavir The metabolism of Atazanavir can be decreased when combined with Methimazole. Atenolol The excretion of Atenolol can be decreased when combined with Methimazole. Atogepant The serum concentration of Atogepant can be increased when it is combined with Methimazole. Atomoxetine The metabolism of Atomoxetine can be decreased when combined with Methimazole. Atorvastatin The metabolism of Atorvastatin can be decreased when combined with Methimazole. Atovaquone The metabolism of Atovaquone can be decreased when combined with Methimazole. Auranofin Methimazole may decrease the excretion rate of Auranofin which could result in a higher serum level. Aurothioglucose Methimazole may decrease the excretion rate of Aurothioglucose which could result in a higher serum level. Avacopan The metabolism of Avacopan can be decreased when combined with Methimazole. Avanafil The metabolism of Avanafil can be decreased when combined with Methimazole. Avapritinib The metabolism of Avapritinib can be decreased when combined with Methimazole. Axitinib The metabolism of Axitinib can be decreased when combined with Methimazole. Azacitidine The risk or severity of adverse effects can be increased when Methimazole is combined with Azacitidine. Azathioprine The risk or severity of adverse effects can be increased when Methimazole is combined with Azathioprine. Azelaic acid Azelaic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Azelastine The metabolism of Azelastine can be decreased when combined with Methimazole. Azithromycin The metabolism of Azithromycin can be decreased when combined with Methimazole. Aztreonam Aztreonam may decrease the excretion rate of Methimazole which could result in a higher serum level. Bacillus calmette-g The risk or severity of infection can be increased when Bacillus calmette-guerin substrain connaught live antigen is combined with Methimazole. Bacillus The therapeutic efficacy of Bacillus calmette-guerin substrain russian BCG-I live antigen can be decreased when used in combination with Methimazole. Bacillus calmette-gueri The risk or severity of infection can be increased when Bacillus calmette-guerin substrain tice live antigen is combined with Methimazole. Bacitracin Bacitracin may decrease the excretion rate of Methimazole which could result in a higher serum level. Baclofen Baclofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Balsalazide Balsalazide may decrease the excretion rate of Methimazole which could result in a higher serum level. Baricitinib The metabolism of Baricitinib can be decreased when combined with Methimazole. Basiliximab The risk or severity of adverse effects can be increased when Basiliximab is combined with Methimazole. BCG vaccine The risk or severity of infection can be increased when BCG vaccine is combined with Methimazole. Beclomethasone d The metabolism of Beclomethasone dipropionate can be decreased when combined with Methimazole. Bedaquiline The metabolism of Bedaquiline can be decreased when combined with Methimazole. Belatacept The risk or severity of adverse effects can be increased when Methimazole is combined with Belatacept. Belimumab The risk or severity of adverse effects can be increased when Methimazole is combined with Belimumab. Belinostat The risk or severity of adverse effects can be increased when Methimazole is combined with Belinostat. Belumosudil The metabolism of Belumosudil can be decreased when combined with Methimazole. Belzutifan The serum concentration of Belzutifan can be increased when it is combined with Methimazole. Bemiparin Methimazole may increase the anticoagulant activities of Bemiparin. Bendamustine The risk or severity of adverse effects can be increased when Methimazole is combined with Bendamustine. Bendroflumethiazide Bendroflumethiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Benorilate Benorilate may decrease the excretion rate of Methimazole which could result in a higher serum level. Benoxaprofen Benoxaprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Benserazide Methimazole may decrease the excretion rate of Benserazide which could result in a higher serum level. Benzatropine The metabolism of Benzatropine can be decreased when combined with Methimazole. Benznidazole Methimazole may decrease the excretion rate of Benznidazole which could result in a higher serum level. Benzocaine The metabolism of Benzocaine can be decreased when combined with Methimazole. Benzphetamine The metabolism of Benzphetamine can be decreased when combined with Methimazole. Benzthiazide Benzthiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Benzydamine Benzydamine may decrease the excretion rate of Methimazole which could result in a higher serum level. Benzyl alcohol The metabolism of Benzyl alcohol can be decreased when combined with Methimazole. Bepotastine Methimazole may decrease the excretion rate of Bepotastine which could result in a higher serum level. Bepridil The metabolism of Bepridil can be decreased when combined with Methimazole. Betamethasone The metabolism of Betamethasone can be decreased when combined with Methimazole. Betamethasone The metabolism of Betamethasone phosphate can be decreased when combined with Methimazole. Betaxolol The excretion of Betaxolol can be decreased when combined with Methimazole. Betrixaban Methimazole may increase the anticoagulant activities of Betrixaban. Bexarotene The metabolism of Bexarotene can be decreased when combined with Methimazole. Bezafibrate The metabolism of Bezafibrate can be decreased when combined with Methimazole. Bicalutamide The metabolism of Bicalutamide can be decreased when combined with Methimazole. Bicisate Methimazole may decrease the excretion rate of Bicisate which could result in a higher serum level. Bictegravir The metabolism of Bictegravir can be decreased when combined with Methimazole. Bimekizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Bimekizumab. Binimetinib The metabolism of Binimetinib can be decreased when combined with Methimazole. Bismuth subgallate Methimazole may decrease the excretion rate of Bismuth subgallate which could result in a higher serum level. Bisoprolol The excretion of Bisoprolol can be decreased when combined with Methimazole. Bisoxatin Methimazole may decrease the excretion rate of Bisoxatin which could result in a higher serum level. Bivalirudin Methimazole may increase the anticoagulant activities of Bivalirudin. Bleomycin The risk or severity of adverse effects can be increased when Bleomycin is combined with Methimazole. Blinatumomab The risk or severity of adverse effects can be increased when Methimazole is combined with Blinatumomab. Boceprevir The metabolism of Boceprevir can be decreased when combined with Methimazole. Bordetella pertussis tox The therapeutic efficacy of Bordetella pertussis toxoid antigen (formaldehyde, glutaraldehyde inactivated) can be decreased when used in combination with Methimazole. Bortezomib The metabolism of Bortezomib can be decreased when combined with Methimazole. Bosentan The metabolism of Bosentan can be decreased when combined with Methimazole. Bosutinib The metabolism of Bosutinib can be decreased when combined with Methimazole. Brentuximab vedotin The metabolism of Brentuximab vedotin can be decreased when combined with Methimazole. Brexpiprazole The metabolism of Brexpiprazole can be decreased when combined with Methimazole. Brigatinib The metabolism of Brigatinib can be decreased when combined with Methimazole. Brivaracetam The metabolism of Brivaracetam can be decreased when combined with Methimazole. Brodalumab The risk or severity of adverse effects can be increased when Methimazole is combined with Brodalumab. Bromazepam The metabolism of Bromazepam can be decreased when combined with Methimazole. Bromocriptine The serum concentration of Bromocriptine can be increased when it is combined with Methimazole. Bromotheophylline Methimazole may decrease the excretion rate of Bromotheophylline which could result in a higher serum level. Brompheniramine The metabolism of Brompheniramine can be decreased when combined with Methimazole. Budesonide The metabolism of Budesonide can be decreased when combined with Methimazole. Bumadizone Bumadizone may decrease the excretion rate of Methimazole which could result in a higher serum level. Bumetanide Bumetanide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Bupivacaine The metabolism of Bupivacaine can be decreased when combined with Methimazole. Buprenorphine The metabolism of Buprenorphine can be decreased when combined with Methimazole. Bupropion The serum concentration of Bupropion can be increased when it is combined with Methimazole. Buspirone The metabolism of Buspirone can be decreased when combined with Methimazole. Busulfan The metabolism of Busulfan can be decreased when combined with Methimazole. Butabarbital Butabarbital may decrease the excretion rate of Methimazole which could result in a higher serum level. Butriptyline The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Butriptyline. Cabazitaxel The metabolism of Cabazitaxel can be decreased when combined with Methimazole. Cabergoline The metabolism of Cabergoline can be decreased when combined with Methimazole. Cabozantinib The metabolism of Cabozantinib can be decreased when combined with Methimazole. Caffeine Methimazole may decrease the excretion rate of Caffeine which could result in a higher serum level. Calcitriol The metabolism of Calcitriol can be decreased when combined with Methimazole. Canagliflozin The metabolism of Canagliflozin can be decreased when combined with Methimazole. Canakinumab The risk or severity of adverse effects can be increased when Methimazole is combined with Canakinumab. Candesartan cilexetil The metabolism of Candesartan cilexetil can be decreased when combined with Methimazole. Cangrelor Methimazole may increase the anticoagulant activities of Cangrelor. Cannabidiol The metabolism of Cannabidiol can be decreased when combined with Methimazole. Canrenoic acid Canrenoic acid may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Capecitabine The metabolism of Capecitabine can be decreased when combined with Methimazole. Caplacizumab The risk or severity of bleeding can be increased when Caplacizumab is combined with Methimazole. Capmatinib The metabolism of Capmatinib can be decreased when combined with Methimazole. Capreomycin Methimazole may decrease the excretion rate of Capreomycin which could result in a higher serum level. Capsaicin The metabolism of Capsaicin can be decreased when combined with Methimazole. Carbamazepine The metabolism of Carbamazepine can be decreased when combined with Methimazole. Carbidopa Carbidopa may decrease the excretion rate of Methimazole which could result in a higher serum level. Carboplatin The risk or severity of adverse effects can be increased when Methimazole is combined with Carboplatin. Carfilzomib The risk or severity of adverse effects can be increased when Methimazole is combined with Carfilzomib. Cariprazine The metabolism of Cariprazine can be decreased when combined with Methimazole. Carisoprodol The metabolism of Carisoprodol can be decreased when combined with Methimazole. Carmustine The risk or severity of adverse effects can be increased when Carmustine is combined with Methimazole. Carprofen Carprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Carteolol The excretion of Carteolol can be decreased when combined with Methimazole. Carvedilol The excretion of Carvedilol can be decreased when combined with Methimazole. Cefaclor Cefaclor may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefadroxil Cefadroxil may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefalotin Cefalotin may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefamandole Cefamandole may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefapirin Cefapirin may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefazolin Cefazolin may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefdinir Cefdinir may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefditoren Cefditoren may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefepime Cefepime may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefmenoxime Cefmenoxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefmetazole Cefmetazole may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefonicid Cefonicid may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefoperazone Cefoperazone may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceforanide Ceforanide may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefotaxime Cefotaxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefotetan Cefotetan may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefotiam Cefotiam may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefoxitin Cefoxitin may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefpiramide Cefpiramide may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefpirome Cefpirome may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefpodoxime Cefpodoxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefprozil Cefprozil may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefradine Cefradine may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftaroline fosamil Ceftaroline fosamil may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftazidime Ceftazidime may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftibuten Ceftibuten may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftizoxime Ceftizoxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftobiprole Ceftobiprole may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceftolozane Methimazole may decrease the excretion rate of Ceftolozane which could result in a higher serum level. Ceftriaxone Ceftriaxone may decrease the excretion rate of Methimazole which could result in a higher serum level. Cefuroxime Cefuroxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Celecoxib The metabolism of Celecoxib can be decreased when combined with Methimazole. Celiprolol The excretion of Celiprolol can be decreased when combined with Methimazole. Cenobamate The metabolism of Cenobamate can be decreased when combined with Methimazole. Cephalexin The metabolism of Cephalexin can be decreased when combined with Methimazole. Cephaloglycin Cephaloglycin may decrease the excretion rate of Methimazole which could result in a higher serum level. Ceritinib The metabolism of Ceritinib can be decreased when combined with Methimazole. Cerivastatin The metabolism of Cerivastatin can be decreased when combined with Methimazole. Certolizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Certolizumab pegol. Cetirizine Cetirizine may decrease the excretion rate of Methimazole which could result in a higher serum level. Cevimeline The metabolism of Cevimeline can be decreased when combined with Methimazole. Chenodeoxycholic acid The metabolism of Chenodeoxycholic acid can be decreased when combined with Methimazole. Chloral hydrate Methimazole may decrease the excretion rate of Chloral hydrate which could result in a higher serum level. Chlorambucil The risk or severity of adverse effects can be increased when Chlorambucil is combined with Methimazole. Chloramphenicol The risk or severity of adverse effects can be increased when Chloramphenicol is combined with Methimazole. Chloroquine The metabolism of Chloroquine can be decreased when combined with Methimazole. Chlorothiazide Chlorothiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Chlorpheniramine The metabolism of Chlorpheniramine can be decreased when combined with Methimazole. Chlorpromazine The metabolism of Chlorpromazine can be decreased when combined with Methimazole. Chlorpropamide The therapeutic efficacy of Chlorpropamide can be decreased when used in combination with Methimazole. Chlorthalidone Chlorthalidone may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Chlorzoxazone The metabolism of Chlorzoxazone can be decreased when combined with Methimazole. Cholecalciferol The metabolism of Cholecalciferol can be decreased when combined with Methimazole. Choline C 11 Methimazole may decrease the excretion rate of Choline C 11 which could result in a higher serum level. Choline magnesium t Choline magnesium trisalicylate may decrease the excretion rate of Methimazole which could result in a higher serum level. Choline salicylate Methimazole may decrease the excretion rate of Choline salicylate which could result in a higher serum level. Chondroitin sulfate Methimazole may decrease the excretion rate of Chondroitin sulfate which could result in a higher serum level. Chromic chloride Methimazole may decrease the excretion rate of Chromic chloride which could result in a higher serum level. Chromic nitrate Methimazole may decrease the excretion rate of Chromic nitrate which could result in a higher serum level. Chromium Methimazole may decrease the excretion rate of Chromium which could result in a higher serum level. Chromium gluconate Methimazole may decrease the excretion rate of Chromium gluconate which could result in a higher serum level. Chromium nicotinate Methimazole may decrease the excretion rate of Chromium nicotinate which could result in a higher serum level. Chromous sulfate Methimazole may decrease the excretion rate of Chromous sulfate which could result in a higher serum level. Ciclesonide The metabolism of Ciclesonide can be decreased when combined with Methimazole. Cidofovir Cidofovir may decrease the excretion rate of Methimazole which could result in a higher serum level. Cilostazol The serum concentration of Cilostazol can be increased when it is combined with Methimazole. Cimetidine Cimetidine may decrease the excretion rate of Methimazole which could result in a higher serum level. Cinacalcet The metabolism of Cinacalcet can be decreased when combined with Methimazole. Cinnarizine The metabolism of Cinnarizine can be decreased when combined with Methimazole. Ciprofloxacin Ciprofloxacin may decrease the excretion rate of Methimazole which could result in a higher serum level. Cisapride The metabolism of Cisapride can be decreased when combined with Methimazole. Cisplatin The risk or severity of adverse effects can be increased when Cisplatin is combined with Methimazole. Citalopram Methimazole may increase the QTc-prolonging activities of Citalopram. Cladribine The risk or severity of adverse effects can be increased when Cladribine is combined with Methimazole. Clarithromycin The metabolism of Clarithromycin can be decreased when combined with Methimazole. Clenbuterol The risk or severity of adverse effects can be increased when Clenbuterol is combined with Methimazole. Clevidipine The metabolism of Clevidipine can be decreased when combined with Methimazole. Clindamycin The metabolism of Clindamycin can be decreased when combined with Methimazole. Clobazam The metabolism of Clobazam can be decreased when combined with Methimazole. Clobetasol propi The metabolism of Clobetasol propionate can be decreased when combined with Methimazole. Clofarabine The risk or severity of adverse effects can be increased when Clofarabine is combined with Methimazole. Clofibrate The metabolism of Clofibrate can be decreased when combined with Methimazole. Clomipramine The metabolism of Clomipramine can be decreased when combined with Methimazole. Clonazepam The metabolism of Clonazepam can be decreased when combined with Methimazole. Clonidine The metabolism of Clonidine can be decreased when combined with Methimazole. Clopidogrel The metabolism of Clopidogrel can be decreased when combined with Methimazole. Clorazepic acid The metabolism of Clorazepic acid can be decreased when combined with Methimazole. Clostridium tetani The therapeutic efficacy of Clostridium tetani toxoid antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Clotiazepam The metabolism of Clotiazepam can be decreased when combined with Methimazole. Clove oil Methimazole may decrease the excretion rate of Clove oil which could result in a higher serum level. Clozapine The serum concentration of Clozapine can be increased when it is combined with Methimazole. Cobicistat The metabolism of Cobicistat can be decreased when combined with Methimazole. Cobimetinib The serum concentration of Cobimetinib can be increased when it is combined with Methimazole. Codeine The metabolism of Codeine can be decreased when combined with Methimazole. Colchicine The metabolism of Colchicine can be decreased when combined with Methimazole. Colistimethate Colistimethate may decrease the excretion rate of Methimazole which could result in a higher serum level. Colistin Methimazole may decrease the excretion rate of Colistin which could result in a higher serum level. Conivaptan The metabolism of Conivaptan can be decreased when combined with Methimazole. Conjugated estrogens The metabolism of Conjugated estrogens can be decreased when combined with Methimazole. Copanlisib The metabolism of Copanlisib can be decreased when combined with Methimazole. Corifollitropin alfa Methimazole may decrease the excretion rate of Corifollitropin alfa which could result in a higher serum level. Corticotropin The metabolism of Corticotropin can be decreased when combined with Methimazole. Cortisone acetate The metabolism of Cortisone acetate can be decreased when combined with Methimazole. Corynebacterium The therapeutic efficacy of Corynebacterium diphtheriae toxoid antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Crizotinib The metabolism of Crizotinib can be decreased when combined with Methimazole. Cyanocobalamin The therapeutic efficacy of Cyanocobalamin can be decreased when used in combination with Methimazole. Cyclandelate The metabolism of Cyclandelate can be decreased when combined with Methimazole. Cyclobenzaprine The metabolism of Cyclobenzaprine can be decreased when combined with Methimazole. Cyclopenthiazide Cyclopenthiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Cyclophosphamide The metabolism of Cyclophosphamide can be decreased when combined with Methimazole. Cyclosporine Methimazole may increase the immunosuppressive activities of Cyclosporine. Cyclothiazide Cyclothiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Cyproterone acetate The metabolism of Cyproterone acetate can be decreased when combined with Methimazole. Cytarabine The risk or severity of adverse effects can be increased when Methimazole is combined with Cytarabine. Dabigatran Methimazole may increase the anticoagulant activities of Dabigatran. Dabigatran etexilate Methimazole may increase the anticoagulant activities of Dabigatran etexilate. Dabrafenib The serum concentration of Dabrafenib can be increased when it is combined with Methimazole. Dacarbazine The risk or severity of adverse effects can be increased when Methimazole is combined with Dacarbazine. Daclatasvir The metabolism of Daclatasvir can be decreased when combined with Methimazole. Dacomitinib The metabolism of Dacomitinib can be decreased when combined with Methimazole. Dactinomycin The risk or severity of adverse effects can be increased when Methimazole is combined with Dactinomycin. Dalfampridine Methimazole may decrease the excretion rate of Dalfampridine which could result in a higher serum level. Dalteparin Methimazole may increase the anticoagulant activities of Dalteparin. Danaparoid Methimazole may increase the anticoagulant activities of Danaparoid. Dapagliflozin The metabolism of Dapagliflozin can be decreased when combined with Methimazole. Dapsone The metabolism of Dapsone can be decreased when combined with Methimazole. Daptomycin Daptomycin may decrease the excretion rate of Methimazole which could result in a higher serum level. Daridorexant The metabolism of Daridorexant can be decreased when combined with Methimazole. Darifenacin The metabolism of Darifenacin can be decreased when combined with Methimazole. Darolutamide The serum concentration of Darolutamide can be increased when it is combined with Methimazole. Darunavir The metabolism of Darunavir can be decreased when combined with Methimazole. Dasabuvir The metabolism of Dasabuvir can be decreased when combined with Methimazole. Dasatinib The metabolism of Dasatinib can be decreased when combined with Methimazole. Daunorubicin The risk or severity of adverse effects can be increased when Daunorubicin is combined with Methimazole. Debrisoquine The metabolism of Debrisoquine can be decreased when combined with Methimazole. Decitabine The risk or severity of adverse effects can be increased when Methimazole is combined with Decitabine. Deferiprone Methimazole may decrease the excretion rate of Deferiprone which could result in a higher serum level. Defibrotide Methimazole may increase the anticoagulant activities of Defibrotide. Deflazacort The serum concentration of Deflazacort can be increased when it is combined with Methimazole. Delafloxacin Methimazole may decrease the excretion rate of Delafloxacin which could result in a higher serum level. Delamanid The metabolism of Delamanid can be decreased when combined with Methimazole. Delavirdine The metabolism of Delavirdine can be decreased when combined with Methimazole. Denosumab The risk or severity of adverse effects can be increased when Denosumab is combined with Methimazole. Desipramine The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Desipramine. Desirudin Methimazole may increase the anticoagulant activities of Desirudin. Deslanoside The serum concentration of Deslanoside can be increased when it is combined with Methimazole. Desmopressin Desmopressin may decrease the excretion rate of Methimazole which could result in a higher serum level. Desogestrel The metabolism of Desogestrel can be decreased when combined with Methimazole. Desoximetasone The risk or severity of adverse effects can be increased when Desoximetasone is combined with Methimazole. Desoxycorticosterone The metabolism of Desoxycorticosterone acetate can be decreased when combined with Methimazole. Desvenlafaxine The metabolism of Desvenlafaxine can be decreased when combined with Methimazole. Deucravacitinib The therapeutic efficacy of Methimazole can be decreased when used in combination with Deucravacitinib. Deutetrabenazine The metabolism of Deutetrabenazine can be decreased when combined with Methimazole. Dexamethasone The metabolism of Dexamethasone can be decreased when combined with Methimazole. Dexamethasone acetate The metabolism of Dexamethasone acetate can be decreased when combined with Methimazole. Dexchlorpheniramine The metabolism of Dexchlorpheniramine maleate can be decreased when combined with Methimazole. Dexfenfluramine The metabolism of Dexfenfluramine can be decreased when combined with Methimazole. Dexibuprofen The metabolism of Dexibuprofen can be decreased when combined with Methimazole. Dexketoprofen Dexketoprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Dexlansoprazole The metabolism of Dexlansoprazole can be decreased when combined with Methimazole. Dexmedetomidine Dexmedetomidine may decrease the excretion rate of Methimazole which could result in a higher serum level. Dexpanthenol Methimazole may decrease the excretion rate of Dexpanthenol which could result in a higher serum level. Dexrazoxane The risk or severity of adverse effects can be increased when Dexrazoxane is combined with Methimazole. Dextran Methimazole may increase the anticoagulant activities of Dextran. Dextroamphetamine The metabolism of Dextroamphetamine can be decreased when combined with Methimazole. Dextromethorphan The metabolism of Dextromethorphan can be decreased when combined with Methimazole. Dextropropoxyphene The metabolism of Dextropropoxyphene can be decreased when combined with Methimazole. Diatrizoate Diatrizoate may decrease the excretion rate of Methimazole which could result in a higher serum level. Diazepam The metabolism of Diazepam can be decreased when combined with Methimazole. Dibenzepin The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Dibenzepin. Dichlorobenzyl alcohol Methimazole may decrease the excretion rate of Dichlorobenzyl alcohol which could result in a higher serum level. Diclofenac The metabolism of Diclofenac can be decreased when combined with Methimazole. Diclofenamide Diclofenamide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Dicoumarol Methimazole may decrease the anticoagulant activities of Dicoumarol. Dicyclomine Methimazole may decrease the excretion rate of Dicyclomine which could result in a higher serum level. Didanosine Methimazole may decrease the excretion rate of Didanosine which could result in a higher serum level. Dienogest The metabolism of Dienogest can be decreased when combined with Methimazole. Diethylpropion The risk or severity of adverse effects can be increased when Diethylpropion is combined with Methimazole. Diethylstilbestrol The metabolism of Diethylstilbestrol can be decreased when combined with Methimazole. Diflunisal Diflunisal may decrease the excretion rate of Methimazole which could result in a higher serum level. Difluocortolone The metabolism of Difluocortolone can be decreased when combined with Methimazole. Digitoxin The serum concentration of Digitoxin can be increased when it is combined with Methimazole. Digoxin The serum concentration of Digoxin can be increased when it is combined with Methimazole. Dihydralazine The metabolism of Dihydralazine can be decreased when combined with Methimazole. Dihydro-alpha- The metabolism of Dihydro-alpha-ergocryptine can be decreased when combined with Methimazole. Dihydrocodeine The metabolism of Dihydrocodeine can be decreased when combined with Methimazole. Dihydroergocornine The serum concentration of Dihydroergocornine can be increased when it is combined with Methimazole. Dihydroergocristine The serum concentration of Dihydroergocristine can be increased when it is combined with Methimazole. Dihydroergotamine The metabolism of Dihydroergotamine can be decreased when combined with Methimazole. Dihydrostreptomycin Dihydrostreptomycin may decrease the excretion rate of Methimazole which could result in a higher serum level. Diltiazem The metabolism of Diltiazem can be decreased when combined with Methimazole. Dimercaprol Methimazole may decrease the excretion rate of Dimercaprol which could result in a higher serum level. Dimethyl fumarate The risk or severity of adverse effects can be increased when Methimazole is combined with Dimethyl fumarate. Dimethyl sulfoxide Methimazole may decrease the excretion rate of Dimethyl sulfoxide which could result in a higher serum level. Dinutuximab The risk or severity of adverse effects can be increased when Methimazole is combined with Dinutuximab. Diphenhydramine The metabolism of Diphenhydramine can be decreased when combined with Methimazole. Dipyridamole Methimazole may increase the anticoagulant activities of Dipyridamole. Diroximel fumarate The risk or severity of adverse effects can be increased when Methimazole is combined with Diroximel fumarate. Disopyramide The metabolism of Disopyramide can be decreased when combined with Methimazole. Disulfiram The metabolism of Disulfiram can be decreased when combined with Methimazole. DL-Methylephedrine Methimazole may decrease the excretion rate of DL-Methylephedrine which could result in a higher serum level. Dobutamine The risk or severity of adverse effects can be increased when Dobutamine is combined with Methimazole. Docetaxel The metabolism of Docetaxel can be decreased when combined with Methimazole. Doconexent The metabolism of Doconexent can be decreased when combined with Methimazole. Dofetilide The metabolism of Dofetilide can be decreased when combined with Methimazole. Dolasetron The metabolism of Dolasetron can be decreased when combined with Methimazole. Domperidone The metabolism of Domperidone can be decreased when combined with Methimazole. Donepezil The metabolism of Donepezil can be decreased when combined with Methimazole. Dopamine The risk or severity of adverse effects can be increased when Dopamine is combined with Methimazole. Doravirine The metabolism of Doravirine can be decreased when combined with Methimazole. Doripenem Methimazole may decrease the excretion rate of Doripenem which could result in a higher serum level. Dosulepin The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Dosulepin. Doxacurium Methimazole may decrease the excretion rate of Doxacurium which could result in a higher serum level. Doxazosin The metabolism of Doxazosin can be decreased when combined with Methimazole. Doxepin The metabolism of Doxepin can be decreased when combined with Methimazole. Doxorubicin The serum concentration of Doxorubicin can be increased when it is combined with Methimazole. Doxycycline Doxycycline may decrease the excretion rate of Methimazole which could result in a higher serum level. Dronabinol The serum concentration of Dronabinol can be increased when it is combined with Methimazole. Dronedarone The metabolism of Dronedarone can be decreased when combined with Methimazole. Drospirenone The metabolism of Drospirenone can be decreased when combined with Methimazole. Drotrecogin alfa Methimazole may increase the anticoagulant activities of Drotrecogin alfa. Droxidopa Methimazole may decrease the excretion rate of Droxidopa which could result in a higher serum level. Duloxetine The metabolism of Duloxetine can be decreased when combined with Methimazole. Duvelisib The metabolism of Duvelisib can be decreased when combined with Methimazole. Dydrogesterone The metabolism of Dydrogesterone can be decreased when combined with Methimazole. Dyphylline Methimazole may decrease the excretion rate of Dyphylline which could result in a higher serum level. Ebastine The metabolism of Ebastine can be decreased when combined with Methimazole. Ebola Zaire va The therapeutic efficacy of Ebola Zaire vaccine (live, attenuated) can be decreased when used in combination with Methimazole. Eculizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Eculizumab. Edetic acid Methimazole may increase the anticoagulant activities of Edetic acid. Edoxaban Methimazole may increase the anticoagulant activities of Edoxaban. Edrophonium Methimazole may decrease the excretion rate of Edrophonium which could result in a higher serum level. Efalizumab The risk or severity of adverse effects can be increased when Efalizumab is combined with Methimazole. Efavirenz The metabolism of Efavirenz can be decreased when combined with Methimazole. Efgartigimod alfa The risk or severity of adverse effects can be increased when Methimazole is combined with Efgartigimod alfa. Elacestrant The serum concentration of Elacestrant can be increased when it is combined with Methimazole. Elagolix The metabolism of Elagolix can be decreased when combined with Methimazole. Elbasvir The metabolism of Elbasvir can be decreased when combined with Methimazole. Eletriptan The metabolism of Eletriptan can be decreased when combined with Methimazole. Elexacaftor The serum concentration of Elexacaftor can be increased when it is combined with Methimazole. Eliglustat The metabolism of Eliglustat can be decreased when combined with Methimazole. Eltrombopag The metabolism of Eltrombopag can be decreased when combined with Methimazole. Elvitegravir The metabolism of Elvitegravir can be decreased when combined with Methimazole. Emapalumab The risk or severity of adverse effects can be increased when Methimazole is combined with Emapalumab. Enalaprilat Methimazole may decrease the excretion rate of Enalaprilat which could result in a higher serum level. Enasidenib The metabolism of Enasidenib can be decreased when combined with Methimazole. Encainide The metabolism of Encainide can be decreased when combined with Methimazole. Encorafenib The metabolism of Encorafenib can be decreased when combined with Methimazole. Enflurane The metabolism of Enflurane can be decreased when combined with Methimazole. Enfortumab vedotin The serum concentration of Enfortumab vedotin can be increased when it is combined with Methimazole. Enoxaparin Methimazole may increase the anticoagulant activities of Enoxaparin. Entecavir The metabolism of Entecavir can be decreased when combined with Methimazole. Entrectinib The metabolism of Entrectinib can be decreased when combined with Methimazole. Enzalutamide The serum concentration of Enzalutamide can be increased when it is combined with Methimazole. Ephedrine The risk or severity of adverse effects can be increased when Ephedrine is combined with Methimazole. Epinastine The metabolism of Epinastine can be decreased when combined with Methimazole. Epinephrine The risk or severity of adverse effects can be increased when Epinephrine is combined with Methimazole. Epirubicin The risk or severity of adverse effects can be increased when Epirubicin is combined with Methimazole. Eplerenone The metabolism of Eplerenone can be decreased when combined with Methimazole. Epoprostenol Methimazole may increase the anticoagulant activities of Epoprostenol. Eptifibatide The risk or severity of bleeding can be increased when Eptifibatide is combined with Methimazole. Eravacycline The metabolism of Eravacycline can be decreased when combined with Methimazole. Erdafitinib The metabolism of Erdafitinib can be decreased when combined with Methimazole. Ergoloid mesylate The serum concentration of Ergoloid mesylate can be increased when it is combined with Methimazole. Ergometrine The serum concentration of Ergometrine can be increased when it is combined with Methimazole. Ergotamine The metabolism of Ergotamine can be decreased when combined with Methimazole. Eribulin The risk or severity of adverse effects can be increased when Methimazole is combined with Eribulin. Erlotinib The metabolism of Erlotinib can be decreased when combined with Methimazole. Ertapenem Ertapenem may decrease the excretion rate of Methimazole which could result in a higher serum level. Erythromycin The metabolism of Erythromycin can be decreased when combined with Methimazole. Escitalopram The metabolism of Escitalopram can be decreased when combined with Methimazole. Esketamine The metabolism of Esketamine can be decreased when combined with Methimazole. Esmolol The excretion of Esmolol can be decreased when combined with Methimazole. Esomeprazole The metabolism of Esomeprazole can be decreased when combined with Methimazole. Estazolam The metabolism of Estazolam can be decreased when combined with Methimazole. Esterified estrogens The metabolism of Esterified estrogens can be decreased when combined with Methimazole. Estetrol The therapeutic efficacy of Methimazole can be decreased when used in combination with Estetrol. Estradiol The metabolism of Estradiol can be decreased when combined with Methimazole. Estradiol acetate The metabolism of Estradiol acetate can be decreased when combined with Methimazole. Estradiol benzoate The metabolism of Estradiol benzoate can be decreased when combined with Methimazole. Estradiol cypionate The metabolism of Estradiol cypionate can be decreased when combined with Methimazole. Estradiol dienanthate The metabolism of Estradiol dienanthate can be decreased when combined with Methimazole. Estradiol valerate The metabolism of Estradiol valerate can be decreased when combined with Methimazole. Estramustine The metabolism of Estramustine can be decreased when combined with Methimazole. Estrone sulfate The metabolism of Estrone sulfate can be decreased when combined with Methimazole. Eszopiclone The serum concentration of Eszopiclone can be increased when it is combined with Methimazole. Etacrynic acid Etacrynic acid may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Etafedrine Methimazole may decrease the excretion rate of Etafedrine which could result in a higher serum level. Etanercept The risk or severity of adverse effects can be increased when Etanercept is combined with Methimazole. Ethambutol Ethambutol may decrease the excretion rate of Methimazole which could result in a higher serum level. Ethanol The metabolism of Ethanol can be decreased when combined with Methimazole. Ethinylestradiol The metabolism of Ethinylestradiol can be decreased when combined with Methimazole. Ethionamide The therapeutic efficacy of Methimazole can be decreased when used in combination with Ethionamide. Ethosuximide The metabolism of Ethosuximide can be decreased when combined with Methimazole. Ethynodiol diacetate The metabolism of Ethynodiol diacetate can be decreased when combined with Methimazole. Etilefrine The risk or severity of adverse effects can be increased when Etilefrine is combined with Methimazole. Etodolac The metabolism of Etodolac can be decreased when combined with Methimazole. Etomidate Etomidate may decrease the excretion rate of Methimazole which could result in a higher serum level. Etonogestrel The metabolism of Etonogestrel can be decreased when combined with Methimazole. Etoposide The metabolism of Etoposide can be decreased when combined with Methimazole. Etoricoxib The metabolism of Etoricoxib can be decreased when combined with Methimazole. Etrasimod The risk or severity of immunosuppression can be increased when Methimazole is combined with Etrasimod. Etravirine The metabolism of Etravirine can be decreased when combined with Methimazole. Eucalyptus oil Methimazole may decrease the excretion rate of Eucalyptus oil which could result in a higher serum level. Everolimus The metabolism of Everolimus can be decreased when combined with Methimazole. Exemestane The metabolism of Exemestane can be decreased when combined with Methimazole. Ezogabine Methimazole may decrease the excretion rate of Ezogabine which could result in a higher serum level. Famtozinameran The therapeutic efficacy of Famtozinameran can be decreased when used in combination with Methimazole. Fedratinib The serum concentration of Fedratinib can be increased when it is combined with Methimazole. Felbamate The metabolism of Felbamate can be decreased when combined with Methimazole. Felodipine The metabolism of Felodipine can be decreased when combined with Methimazole. Fenbufen Fenbufen may decrease the excretion rate of Methimazole which could result in a higher serum level. Fenfluramine The metabolism of Fenfluramine can be decreased when combined with Methimazole. Fenofibrate The metabolism of Fenofibrate can be decreased when combined with Methimazole. Fenofibric acid Methimazole may decrease the excretion rate of Fenofibric acid which could result in a higher serum level. Fenoldopam Methimazole may decrease the excretion rate of Fenoldopam which could result in a higher serum level. Fenoprofen Fenoprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Fenoterol The risk or severity of adverse effects can be increased when Fenoterol is combined with Methimazole. Fentanyl The metabolism of Fentanyl can be decreased when combined with Methimazole. Fesoterodine The metabolism of Fesoterodine can be decreased when combined with Methimazole. Fexinidazole The metabolism of Fexinidazole can be decreased when combined with Methimazole. Fezolinetant The serum concentration of Fezolinetant can be increased when it is combined with Methimazole. Filgotinib The risk or severity of adverse effects can be increased when Methimazole is combined with Filgotinib. Finasteride The metabolism of Finasteride can be decreased when combined with Methimazole. Finerenone The serum concentration of the active metabolites of Finerenone can be increased when Finerenone is used in combination with Methimazole. Fingolimod Methimazole may increase the immunosuppressive activities of Fingolimod. Fish oil The metabolism of Fish oil can be decreased when combined with Methimazole. Flavoxate Methimazole may decrease the excretion rate of Flavoxate which could result in a higher serum level. Flecainide The metabolism of Flecainide can be decreased when combined with Methimazole. Flibanserin The metabolism of Flibanserin can be decreased when combined with Methimazole. Floctafenine Floctafenine may decrease the excretion rate of Methimazole which could result in a higher serum level. Florbetaben F-18 Methimazole may decrease the excretion rate of Florbetaben (18F) which could result in a higher serum level. Florbetapir (18F) Methimazole may decrease the excretion rate of Florbetapir (18F) which could result in a higher serum level. Floxuridine The risk or severity of adverse effects can be increased when Floxuridine is combined with Methimazole. Fluconazole Fluconazole may decrease the excretion rate of Methimazole which could result in a higher serum level. Flucytosine The risk or severity of adverse effects can be increased when Methimazole is combined with Flucytosine. Fludarabine The risk or severity of adverse effects can be increased when Methimazole is combined with Fludarabine. Fludeoxyglucose (18F) Methimazole may decrease the excretion rate of Fludeoxyglucose (18F) which could result in a higher serum level. Fludrocortisone The metabolism of Fludrocortisone can be decreased when combined with Methimazole. Fluindione Methimazole may decrease the anticoagulant activities of Fluindione. Flumazenil Methimazole may decrease the excretion rate of Flumazenil which could result in a higher serum level. Flumethasone The metabolism of Flumethasone can be decreased when combined with Methimazole. Flunarizine The metabolism of Flunarizine can be decreased when combined with Methimazole. Flunisolide The metabolism of Flunisolide can be decreased when combined with Methimazole. Flunitrazepam The metabolism of Flunitrazepam can be decreased when combined with Methimazole. Fluocinolone ace The metabolism of Fluocinolone acetonide can be decreased when combined with Methimazole. Fluocinonide The metabolism of Fluocinonide can be decreased when combined with Methimazole. Fluocortolone The metabolism of Fluocortolone can be decreased when combined with Methimazole. Fluorometholone The risk or severity of adverse effects can be increased when Fluorometholone is combined with Methimazole. Fluorouracil The metabolism of Fluorouracil can be decreased when combined with Methimazole. Fluoxetine The metabolism of Fluoxetine can be decreased when combined with Methimazole. Flupentixol The risk or severity of myelosuppression can be increased when Flupentixol is combined with Methimazole. Fluprednisolone The metabolism of Fluprednisolone can be decreased when combined with Methimazole. Flurazepam The metabolism of Flurazepam can be decreased when combined with Methimazole. Flurbiprofen The metabolism of Flurbiprofen can be decreased when combined with Methimazole. Fluspirilene The metabolism of Fluspirilene can be decreased when combined with Methimazole. Flutamide The metabolism of Flutamide can be decreased when combined with Methimazole. Fluticasone The risk or severity of adverse effects can be increased when Methimazole is combined with Fluticasone. Fluticasone furoate The serum concentration of Fluticasone furoate can be increased when it is combined with Methimazole. Fluticasone propionate The serum concentration of Fluticasone propionate can be increased when it is combined with Methimazole. Fluvastatin The metabolism of Fluvastatin can be decreased when combined with Methimazole. Fluvoxamine The metabolism of Fluvoxamine can be decreased when combined with Methimazole. Folic acid Folic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Fomepizole Methimazole may decrease the excretion rate of Fomepizole which could result in a higher serum level. Fondaparinux Methimazole may increase the anticoagulant activities of Fondaparinux. Formestane Methimazole may decrease the excretion rate of Formestane which could result in a higher serum level. Formoterol The metabolism of Formoterol can be decreased when combined with Methimazole. Fosamprenavir The metabolism of Fosamprenavir can be decreased when combined with Methimazole. Fosaprepitant The metabolism of Fosaprepitant can be decreased when combined with Methimazole. Foscarnet Foscarnet may decrease the excretion rate of Methimazole which could result in a higher serum level. Fosfomycin Methimazole may decrease the excretion rate of Fosfomycin which could result in a higher serum level. Fosinopril Fosinopril may decrease the excretion rate of Methimazole which could result in a higher serum level. Fosnetupitant The metabolism of Fosnetupitant can be decreased when combined with Methimazole. Fosphenytoin The metabolism of Fosphenytoin can be decreased when combined with Methimazole. Fostamatinib The metabolism of Fostamatinib can be decreased when combined with Methimazole. Fostemsavir The metabolism of Fostemsavir can be decreased when combined with Methimazole. Framycetin Framycetin may decrease the excretion rate of Methimazole which could result in a higher serum level. Frovatriptan The metabolism of Frovatriptan can be decreased when combined with Methimazole. Furosemide Furosemide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Fusidic acid The metabolism of Fusidic acid can be decreased when combined with Methimazole. Futibatinib The metabolism of Futibatinib can be decreased when combined with Methimazole. Gabapentin enacarbil Methimazole may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level. Gadobenic acid Gadobenic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Gadodiamide Gadodiamide may decrease the excretion rate of Methimazole which could result in a higher serum level. Gadofosveset trisodium Methimazole may decrease the excretion rate of Gadofosveset trisodium which could result in a higher serum level. Gadopentetic acid Methimazole may decrease the excretion rate of Gadopentetic acid which could result in a higher serum level. Gadoteric acid Methimazole may decrease the excretion rate of Gadoteric acid which could result in a higher serum level. Gadoteridol Gadoteridol may decrease the excretion rate of Methimazole which could result in a higher serum level. Galantamine The metabolism of Galantamine can be decreased when combined with Methimazole. Ganciclovir Methimazole may decrease the excretion rate of Ganciclovir which could result in a higher serum level. Gefitinib The metabolism of Gefitinib can be decreased when combined with Methimazole. Gemcitabine The risk or severity of adverse effects can be increased when Gemcitabine is combined with Methimazole. Gemfibrozil The metabolism of Gemfibrozil can be decreased when combined with Methimazole. Gemtuzumab ozo The risk or severity of adverse effects can be increased when Gemtuzumab ozogamicin is combined with Methimazole. Gentamicin Methimazole may decrease the excretion rate of Gentamicin which could result in a higher serum level. Gestrinone The metabolism of Gestrinone can be decreased when combined with Methimazole. Gilteritinib The metabolism of Gilteritinib can be decreased when combined with Methimazole. Gimeracil Methimazole may decrease the excretion rate of Gimeracil which could result in a higher serum level. Givosiran Givosiran may decrease the excretion rate of Methimazole which could result in a higher serum level. Glasdegib The serum concentration of Glasdegib can be increased when it is combined with Methimazole. Glatiramer The risk or severity of adverse effects can be increased when Methimazole is combined with Glatiramer. Gliclazide The therapeutic efficacy of Gliclazide can be decreased when used in combination with Methimazole. Glimepiride The therapeutic efficacy of Glimepiride can be decreased when used in combination with Methimazole. Glipizide The therapeutic efficacy of Glipizide can be decreased when used in combination with Methimazole. Gliquidone The therapeutic efficacy of Gliquidone can be decreased when used in combination with Methimazole. Glyburide The metabolism of Glyburide can be decreased when combined with Methimazole. Glycerol phenylb Methimazole may decrease the excretion rate of Glycerol phenylbutyrate which could result in a higher serum level. Golimumab The risk or severity of adverse effects can be increased when Methimazole is combined with Golimumab. Golodirsen Methimazole may decrease the excretion rate of Golodirsen which could result in a higher serum level. Goserelin Goserelin may decrease the excretion rate of Methimazole which could result in a higher serum level. Granisetron The metabolism of Granisetron can be decreased when combined with Methimazole. Grazoprevir The metabolism of Grazoprevir can be decreased when combined with Methimazole. Grepafloxacin The metabolism of Grepafloxacin can be decreased when combined with Methimazole. GSK-3844766A The therapeutic efficacy of GSK-3844766A can be decreased when used in combination with Methimazole. Guanabenz The metabolism of Guanabenz can be decreased when combined with Methimazole. Guanethidine Methimazole may decrease the excretion rate of Guanethidine which could result in a higher serum level. Guanfacine The metabolism of Guanfacine can be decreased when combined with Methimazole. Guselkumab The risk or severity of adverse effects can be increased when Methimazole is combined with Guselkumab. Haemophilus in The therapeutic efficacy of Haemophilus influenzae type B strain 20752 capsular polysaccharide tetanus toxoid conjugate antigen can be decreased when used in combination with Methimazole. Halofantrine The metabolism of Halofantrine can be decreased when combined with Methimazole. Haloperidol The serum concentration of Haloperidol can be increased when it is combined with Methimazole. Halothane The metabolism of Halothane can be decreased when combined with Methimazole. Heparin Methimazole may increase the anticoagulant activities of Heparin. Hepatitis A Vaccine The therapeutic efficacy of Hepatitis A Vaccine can be decreased when used in combination with Methimazole. Hepatitis B Vaccine (Recombinant) The therapeutic efficacy of Hepatitis B Vaccine (Recombinant) can be decreased when used in combination with Methimazole. Human ad The risk or severity of infection can be increased when Human adenovirus e serotype 4 strain cl-68578 antigen is combined with Methimazole. Hydralazine Methimazole may decrease the excretion rate of Hydralazine which could result in a higher serum level. Hydrochlorothiazide Hydrochlorothiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Hydrocodone The metabolism of Hydrocodone can be decreased when combined with Methimazole. Hydrocortisone The metabolism of Hydrocortisone can be decreased when combined with Methimazole. Hydrocortisone acetate The metabolism of Hydrocortisone acetate can be decreased when combined with Methimazole. Hydrocortisone butyrate The metabolism of Hydrocortisone butyrate can be decreased when combined with Methimazole. Hydrocortisone cypionate The metabolism of Hydrocortisone cypionate can be decreased when combined with Methimazole. Hydrocortisone phosphate The metabolism of Hydrocortisone phosphate can be decreased when combined with Methimazole. Hydrocortisone succinate The metabolism of Hydrocortisone succinate can be decreased when combined with Methimazole. Hydroflumethiazide Hydroflumethiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Hydromorphone The metabolism of Hydromorphone can be decreased when combined with Methimazole. Hydroxocobalamin Hydroxocobalamin may decrease the excretion rate of Methimazole which could result in a higher serum level. Hydroxychloroquine The metabolism of Hydroxychloroquine can be decreased when combined with Methimazole. Hydroxyethyl Starch Methimazole may decrease the excretion rate of Hydroxyethyl Starch which could result in a higher serum level. Hydroxyprogeste The metabolism of Hydroxyprogesterone caproate can be decreased when combined with Methimazole. Hydroxyurea The risk or severity of adverse effects can be increased when Methimazole is combined with Hydroxyurea. Hydroxyzine The metabolism of Hydroxyzine can be decreased when combined with Methimazole. Ibrexafungerp The serum concentration of Ibrexafungerp can be increased when it is combined with Methimazole. Ibritumomab tiuxetan The risk or severity of adverse effects can be increased when Ibritumomab tiuxetan is combined with Methimazole. Ibrutinib The metabolism of Ibrutinib can be decreased when combined with Methimazole. Ibuprofen The metabolism of Ibuprofen can be decreased when combined with Methimazole. Ibutilide Ibutilide may decrease the excretion rate of Methimazole which could result in a higher serum level. Icatibant Methimazole may decrease the excretion rate of Icatibant which could result in a higher serum level. Icosapent Icosapent may decrease the excretion rate of Methimazole which could result in a higher serum level. Icosapent ethyl The risk or severity of bleeding can be increased when Icosapent ethyl is combined with Methimazole. Idarubicin The risk or severity of adverse effects can be increased when Methimazole is combined with Idarubicin. Idarucizumab Methimazole may decrease the excretion rate of Idarucizumab which could result in a higher serum level. Idebenone Methimazole may decrease the excretion rate of Idebenone which could result in a higher serum level. Idelalisib The metabolism of Idelalisib can be decreased when combined with Methimazole. Ifosfamide The metabolism of Ifosfamide can be decreased when combined with Methimazole. Iloperidone The metabolism of Iloperidone can be decreased when combined with Methimazole. Iloprost The risk or severity of bleeding can be increased when Iloprost is combined with Methimazole. Imatinib The serum concentration of Imatinib can be increased when it is combined with Methimazole. Imipramine The metabolism of Imipramine can be decreased when combined with Methimazole. Indacaterol The metabolism of Indacaterol can be decreased when combined with Methimazole. Indapamide The metabolism of Indapamide can be decreased when combined with Methimazole. Indigotindisulfonic acid Methimazole may decrease the excretion rate of Indigotindisulfonic acid which could result in a higher serum level. Indinavir The metabolism of Indinavir can be decreased when combined with Methimazole. Indomethacin The risk or severity of adverse effects can be increased when Indomethacin is combined with Methimazole. Inebilizumab The risk or severity of infection can be increased when Methimazole is combined with Inebilizumab. Infigratinib The metabolism of Infigratinib can be decreased when combined with Methimazole. Infliximab The risk or severity of adverse effects can be increased when Infliximab is combined with Methimazole. Influenza A virus The therapeutic efficacy of Influenza A virus A/Brisbane/59/2007(H1N1) antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza The therapeutic efficacy of Influenza A virus A/Brisbane/59/2007(H1N1) hemagglutinin antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza A virus The therapeutic efficacy of Influenza A virus A/California/7/2009 (H1N1) live (attenuated) antigen can be decreased when used in combination with Methimazole. Influenza A virus A The therapeutic efficacy of Influenza A virus A/California/7/2009 X-181 (H1N1) antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza A virus The therapeutic efficacy of Influenza A virus A/California/7/2009 X-181 (H1N1) hemagglutinin antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza A vir The therapeutic efficacy of Influenza A virus A/Perth/16/2009 (H3N2) live (attenuated) antigen can be decreased when used in combination with Methimazole. Influenza A virus The therapeutic efficacy of Influenza A virus A/Uruguay/716/2007(H3N2) antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza A virus The therapeutic efficacy of Influenza A virus A/Victoria/210/2009 X-187 (H3N2) antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Influenza A vir The therapeutic efficacy of Influenza A virus A/Victoria/210/2009 X-187 (H3N2) hemagglutinin antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Influenza B virus The therapeutic efficacy of Influenza B virus B/Brisbane/60/2008 antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. propiolactone inactivated) The therapeutic efficacy of Influenza B virus B/Brisbane/60/2008 antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Influenza B The therapeutic efficacy of Influenza B virus B/Brisbane/60/2008 hemagglutinin antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Influenza B v The therapeutic efficacy of Influenza B virus B/Brisbane/60/2008 hemagglutinin antigen (propiolactone inactivated) can be decreased when used in combination with Methimazole. Inosine pranobex Methimazole may decrease the excretion rate of Inosine pranobex which could result in a higher serum level. Inositol Methimazole may decrease the excretion rate of Inositol which could result in a higher serum level. Inotersen Inotersen may decrease the excretion rate of Methimazole which could result in a higher serum level. Insulin aspart The therapeutic efficacy of Insulin aspart can be decreased when used in combination with Methimazole. Insulin beef The therapeutic efficacy of Insulin beef can be decreased when used in combination with Methimazole. Insulin degludec The therapeutic efficacy of Insulin degludec can be decreased when used in combination with Methimazole. Insulin detemir The therapeutic efficacy of Insulin detemir can be decreased when used in combination with Methimazole. Insulin glargine The therapeutic efficacy of Insulin glargine can be decreased when used in combination with Methimazole. Insulin glulisine The therapeutic efficacy of Insulin glulisine can be decreased when used in combination with Methimazole. Insulin human The therapeutic efficacy of Insulin human can be decreased when used in combination with Methimazole. Insulin lispro The therapeutic efficacy of Insulin lispro can be decreased when used in combination with Methimazole. Insulin pork The therapeutic efficacy of Insulin pork can be decreased when used in combination with Methimazole. Interferon alfa-2a The risk or severity of adverse effects can be increased when Interferon alfa-2a is combined with Methimazole. Interferon alfa-2b The risk or severity of adverse effects can be increased when Interferon alfa-2b is combined with Methimazole. Interferon alfa-n1 The risk or severity of adverse effects can be increased when Interferon alfa-n1 is combined with Methimazole. Interferon alfa-n3 The risk or severity of adverse effects can be increased when Interferon alfa-n3 is combined with Methimazole. Interferon alfacon-1 The risk or severity of adverse effects can be increased when Interferon alfacon-1 is combined with Methimazole. Interferon beta-1b The risk or severity of adverse effects can be increased when Interferon beta-1b is combined with Methimazole. Interferon gamma-1b The risk or severity of adverse effects can be increased when Interferon gamma-1b is combined with Methimazole. Iobenguane sulfate Methimazole may decrease the excretion rate of Iobenguane sulfate I-123 which could result in a higher serum level. Iodide I-131 The therapeutic efficacy of Iodide I-131 can be decreased when used in combination with Methimazole. Iodixanol Methimazole may decrease the excretion rate of Iodixanol which could result in a higher serum level. Iofetamine I-123 The risk or severity of adverse effects can be increased when Iofetamine I-123 is combined with Methimazole. Ioflupane I-123 Methimazole may decrease the excretion rate of Ioflupane I-123 which could result in a higher serum level. Iopromide Methimazole may decrease the excretion rate of Iopromide which could result in a higher serum level. Iothalamic acid Methimazole may decrease the excretion rate of Iothalamic acid which could result in a higher serum level. Ioversol Methimazole may decrease the excretion rate of Ioversol which could result in a higher serum level. Ioxilan Methimazole may decrease the excretion rate of Ioxilan which could result in a higher serum level. Ipecac The metabolism of Ipecac can be decreased when combined with Methimazole. Ipilimumab Methimazole may decrease the excretion rate of Ipilimumab which could result in a higher serum level. Irbesartan The metabolism of Irbesartan can be decreased when combined with Methimazole. Irinotecan The serum concentration of SN-38, an active metabolite of Irinotecan, can be increased when used in combination with Methimazole. Isavuconazole The metabolism of Isavuconazole can be decreased when combined with Methimazole. Isavuconazonium The metabolism of Isavuconazonium can be decreased when combined with Methimazole. Isoflurane The metabolism of Isoflurane can be decreased when combined with Methimazole. Isoniazid Methimazole may decrease the excretion rate of Isoniazid which could result in a higher serum level. Isoprenaline The risk or severity of adverse effects can be increased when Isoprenaline is combined with Methimazole. Isosorbide Isosorbide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Isosorbide mononitrate Methimazole may decrease the excretion rate of Isosorbide mononitrate which could result in a higher serum level. Isosulfan blue Methimazole may decrease the excretion rate of Isosulfan blue which could result in a higher serum level. Isotretinoin The metabolism of Isotretinoin can be decreased when combined with Methimazole. Isoxicam Isoxicam may decrease the excretion rate of Methimazole which could result in a higher serum level. Isoxsuprine The risk or severity of adverse effects can be increased when Isoxsuprine is combined with Methimazole. Isradipine The metabolism of Isradipine can be decreased when combined with Methimazole. Istradefylline The metabolism of Istradefylline can be decreased when combined with Methimazole. Itraconazole The metabolism of Itraconazole can be decreased when combined with Methimazole. Ivabradine The metabolism of Ivabradine can be decreased when combined with Methimazole. Ivacaftor The metabolism of Ivacaftor can be decreased when combined with Methimazole. Ivermectin The metabolism of Ivermectin can be decreased when combined with Methimazole. Ivosidenib The metabolism of Ivosidenib can be decreased when combined with Methimazole. Ixabepilone The metabolism of Ixabepilone can be decreased when combined with Methimazole. Ixazomib The metabolism of Ixazomib can be decreased when combined with Methimazole. Ixekizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Ixekizumab. Janssen COVID-19 Vaccine The therapeutic efficacy of Janssen COVID-19 Vaccine can be decreased when used in combination with Methimazole. Japanese encep The therapeutic efficacy of Japanese encephalitis virus strain sa 14-14-2 antigen (formaldehyde inactivated) can be decreased when used in combination with Methimazole. Kanamycin Methimazole may decrease the excretion rate of Kanamycin which could result in a higher serum level. Ketamine The metabolism of Ketamine can be decreased when combined with Methimazole. Ketazolam The metabolism of Ketazolam can be decreased when combined with Methimazole. Ketoconazole The metabolism of Ketoconazole can be decreased when combined with Methimazole. Ketoprofen Ketoprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Ketorolac The metabolism of Ketorolac can be decreased when combined with Methimazole. Labetalol The excretion of Labetalol can be decreased when combined with Methimazole. Lacidipine The metabolism of Lacidipine can be decreased when combined with Methimazole. Lacosamide The metabolism of Lacosamide can be decreased when combined with Methimazole. Lamivudine Lamivudine may decrease the excretion rate of Methimazole which could result in a higher serum level. Lamotrigine Lamotrigine may decrease the excretion rate of Methimazole which could result in a higher serum level. Lansoprazole The metabolism of Lansoprazole can be decreased when combined with Methimazole. Lapatinib The metabolism of Lapatinib can be decreased when combined with Methimazole. Larotrectinib The metabolism of Larotrectinib can be decreased when combined with Methimazole. Latamoxef Latamoxef may decrease the excretion rate of Methimazole which could result in a higher serum level. Ledipasvir Methimazole may decrease the excretion rate of Ledipasvir which could result in a higher serum level. Lefamulin The serum concentration of Lefamulin can be increased when it is combined with Methimazole. Leflunomide The risk or severity of adverse effects can be increased when Methimazole is combined with Leflunomide. Lemborexant The metabolism of Lemborexant can be decreased when combined with Methimazole. Lenalidomide The risk or severity of adverse effects can be increased when Lenalidomide is combined with Methimazole. Lenvatinib The therapeutic efficacy of Methimazole can be decreased when used in combination with Lenvatinib. Lepirudin Methimazole may increase the anticoagulant activities of Lepirudin. Lercanidipine The metabolism of Lercanidipine can be decreased when combined with Methimazole. Lesinurad The metabolism of Lesinurad can be decreased when combined with Methimazole. Letrozole The metabolism of Letrozole can be decreased when combined with Methimazole. Leuprolide Leuprolide may decrease the excretion rate of Methimazole which could result in a higher serum level. Levacetylmethadol The metabolism of Levacetylmethadol can be decreased when combined with Methimazole. Levamlodipine The serum concentration of Levamlodipine can be increased when it is combined with Methimazole. Levobetaxolol The excretion of Levobetaxolol can be decreased when combined with Methimazole. Levobunolol The excretion of Levobunolol can be decreased when combined with Methimazole. Levobupivacaine The metabolism of Levobupivacaine can be decreased when combined with Methimazole. Levocarnitine Levocarnitine may decrease the excretion rate of Methimazole which could result in a higher serum level. Levocetirizine The metabolism of Levocetirizine can be decreased when combined with Methimazole. Levofloxacin Methimazole may decrease the excretion rate of Levofloxacin which could result in a higher serum level. Levoketoconazole The metabolism of Levoketoconazole can be decreased when combined with Methimazole. Levomenthol The metabolism of Levomenthol can be decreased when combined with Methimazole. Levomilnacipran The metabolism of Levomilnacipran can be decreased when combined with Methimazole. Levonordefrin The risk or severity of adverse effects can be increased when Levonordefrin is combined with Methimazole. Levonorgestrel The metabolism of Levonorgestrel can be decreased when combined with Methimazole. Levosalbutamol Methimazole may decrease the excretion rate of Levosalbutamol which could result in a higher serum level. Lidocaine The metabolism of Lidocaine can be decreased when combined with Methimazole. Lidoflazine The metabolism of Lidoflazine can be decreased when combined with Methimazole. Linagliptin The metabolism of Linagliptin can be decreased when combined with Methimazole. Linezolid The risk or severity of adverse effects can be increased when Linezolid is combined with Methimazole. Liothyronine Liothyronine may decrease the excretion rate of Methimazole which could result in a higher serum level. Liotrix The metabolism of Liotrix can be decreased when combined with Methimazole. Lipegfilgrastim Methimazole may increase the myelosuppressive activities of Lipegfilgrastim. Lisdexamfetamine The serum concentration of dextroamphetamine, an active metabolite of Lisdexamfetamine, can be increased when used in combination with Methimazole. Lisinopril Lisinopril may decrease the excretion rate of Methimazole which could result in a higher serum level. Lisuride The serum concentration of Lisuride can be increased when it is combined with Methimazole. Lithium carbonate Methimazole may decrease the excretion rate of Lithium carbonate which could result in a higher serum level. Lithium citrate Lithium citrate may decrease the excretion rate of Methimazole which could result in a higher serum level. Lixisenatide Methimazole may decrease the excretion rate of Lixisenatide which could result in a higher serum level. Lofexidine The metabolism of Lofexidine can be decreased when combined with Methimazole. Lomefloxacin The metabolism of Lomefloxacin can be decreased when combined with Methimazole. Lomifylline Methimazole may decrease the excretion rate of Lomifylline which could result in a higher serum level. Lomitapide The metabolism of Lomitapide can be decreased when combined with Methimazole. Lomustine The risk or severity of adverse effects can be increased when Methimazole is combined with Lomustine. Lonafarnib The serum concentration of Lonafarnib can be increased when it is combined with Methimazole. Loperamide The metabolism of Loperamide can be decreased when combined with Methimazole. Lopinavir The serum concentration of Methimazole can be increased when it is combined with Lopinavir. Loracarbef Loracarbef may decrease the excretion rate of Methimazole which could result in a higher serum level. Loratadine The metabolism of Loratadine can be decreased when combined with Methimazole. Lorazepam The metabolism of Lorazepam can be decreased when combined with Methimazole. Lorcaserin The metabolism of Lorcaserin can be decreased when combined with Methimazole. Lorlatinib The metabolism of Lorlatinib can be decreased when combined with Methimazole. Lornoxicam The metabolism of Lornoxicam can be decreased when combined with Methimazole. Lorpiprazole The metabolism of Lorpiprazole can be decreased when combined with Methimazole. Losartan The metabolism of Losartan can be decreased when combined with Methimazole. Lovastatin The serum concentration of Lovastatin can be increased when it is combined with Methimazole. Loxoprofen Loxoprofen may decrease the excretion rate of Methimazole which could result in a higher serum level. Lubiprostone Methimazole may decrease the excretion rate of Lubiprostone which could result in a higher serum level. Lumacaftor The serum concentration of Lumacaftor can be increased when it is combined with Methimazole. Lumateperone The serum concentration of Lumateperone can be increased when it is combined with Methimazole. Lumefantrine The metabolism of Lumefantrine can be decreased when combined with Methimazole. Lumiracoxib The metabolism of Lumiracoxib can be decreased when combined with Methimazole. Lurasidone The metabolism of Lurasidone can be decreased when combined with Methimazole. Lurbinectedin The serum concentration of Lurbinectedin can be increased when it is combined with Methimazole. Lynestrenol The metabolism of Lynestrenol can be decreased when combined with Methimazole. Macimorelin The metabolism of Macimorelin can be decreased when combined with Methimazole. Macitentan The metabolism of Macitentan can be decreased when combined with Methimazole. Magnesium The serum concentration of Magnesium can be decreased when it is combined with Methimazole. Magnesium carbonate Methimazole may decrease the excretion rate of Magnesium carbonate which could result in a higher serum level. Magnesium chloride Methimazole may decrease the excretion rate of Magnesium chloride which could result in a higher serum level. Magnesium hydroxide Methimazole may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level. Magnesium trisilicate Methimazole may decrease the excretion rate of Magnesium trisilicate which could result in a higher serum level. Mangafodipir Methimazole may decrease the excretion rate of Mangafodipir which could result in a higher serum level. Manidipine The metabolism of Manidipine can be decreased when combined with Methimazole. Mannitol Mannitol may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Maprotiline The metabolism of Maprotiline can be decreased when combined with Methimazole. Maraviroc The metabolism of Maraviroc can be decreased when combined with Methimazole. Maribavir The metabolism of Maribavir can be decreased when combined with Methimazole. Mavacamten The serum concentration of Mavacamten can be increased when it is combined with Methimazole. Measles virus vac The therapeutic efficacy of Measles virus vaccine live attenuated can be decreased when used in combination with Methimazole. Mecamylamine Mecamylamine may decrease the excretion rate of Methimazole which could result in a higher serum level. Mechlorethamine The risk or severity of adverse effects can be increased when Methimazole is combined with Mechlorethamine. Meclizine The metabolism of Meclizine can be decreased when combined with Methimazole. Meclofenamic acid Meclofenamic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Medrogestone The metabolism of Medrogestone can be decreased when combined with Methimazole. Medroxyprogesterone The metabolism of Medroxyprogesterone acetate can be decreased when combined with Methimazole. Mefenamic acid The metabolism of Mefenamic acid can be decreased when combined with Methimazole. Mefloquine The metabolism of Mefloquine can be decreased when combined with Methimazole. Megestrol acetate The metabolism of Megestrol acetate can be decreased when combined with Methimazole. Melatonin The metabolism of Melatonin can be decreased when combined with Methimazole. Meloxicam The metabolism of Meloxicam can be decreased when combined with Methimazole. Melphalan The risk or severity of adverse effects can be increased when Methimazole is combined with Melphalan. Memantine Methimazole may decrease the excretion rate of Memantine which could result in a higher serum level. Meningococcal The therapeutic efficacy of Meningococcal (groups A, C, Y and W-135) oligosaccharide diphtheria CRM197 conjugate vaccine can be decreased when used in combination with Methimazole. Meperidine The metabolism of Meperidine can be decreased when combined with Methimazole. Mephentermine The risk or severity of adverse effects can be increased when Mephentermine is combined with Methimazole. Mephenytoin The metabolism of Mephenytoin can be decreased when combined with Methimazole. Mepivacaine Methimazole may decrease the excretion rate of Mepivacaine which could result in a higher serum level. Mepolizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Mepolizumab. Meprednisone The metabolism of Meprednisone can be decreased when combined with Methimazole. Mercaptopurine Methimazole may decrease the excretion rate of Mercaptopurine which could result in a higher serum level. Meropenem Meropenem may decrease the excretion rate of Methimazole which could result in a higher serum level. Mesalazine Mesalazine may decrease the excretion rate of Methimazole which could result in a higher serum level. Mesoridazine The metabolism of Mesoridazine can be decreased when combined with Methimazole. Mestranol The metabolism of Mestranol can be decreased when combined with Methimazole. Metamfetamine The metabolism of Metamfetamine can be decreased when combined with Methimazole. Metamizole The risk or severity of myelosuppression can be increased when Metamizole is combined with Methimazole. Metaraminol The risk or severity of adverse effects can be increased when Metaraminol is combined with Methimazole. Metaxalone Metaxalone may decrease the excretion rate of Methimazole which could result in a higher serum level. Metergoline The serum concentration of Metergoline can be increased when it is combined with Methimazole. Metformin Metformin may decrease the excretion rate of Methimazole which could result in a higher serum level. Methadone The metabolism of Methadone can be decreased when combined with Methimazole. Methazolamide Methazolamide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Methotrexate The metabolism of Methotrexate can be decreased when combined with Methimazole. Methotrimeprazine The metabolism of Methotrimeprazine can be decreased when combined with Methimazole. Methoxamine The risk or severity of adverse effects can be increased when Methoxamine is combined with Methimazole. Methoxsalen Methoxsalen may decrease the excretion rate of Methimazole which could result in a higher serum level. Methoxyflurane The metabolism of Methoxyflurane can be decreased when combined with Methimazole. Methoxyphenamine The risk or severity of adverse effects can be increased when Methoxyphenamine is combined with Methimazole. Methsuximide The metabolism of Methsuximide can be decreased when combined with Methimazole. Methyldopa Methimazole may decrease the excretion rate of Methyldopa which could result in a higher serum level. Methylene blue The metabolism of Methylene blue can be decreased when combined with Methimazole. Methylergometrine The serum concentration of Methylergometrine can be increased when it is combined with Methimazole. Methylnaltrexone Methimazole may decrease the excretion rate of Methylnaltrexone which could result in a higher serum level. Methylphenobarbital The metabolism of Methylphenobarbital can be decreased when combined with Methimazole. Methylprednisolone The metabolism of Methylprednisolone can be decreased when combined with Methimazole. Methylprednisone The metabolism of Methylprednisone can be decreased when combined with Methimazole. Methyltestosterone The metabolism of Methyltestosterone can be decreased when combined with Methimazole. Methysergide The serum concentration of Methysergide can be increased when it is combined with Methimazole. Meticrane Meticrane may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Metipranolol The excretion of Metipranolol can be decreased when combined with Methimazole. Metoclopramide The metabolism of Metoclopramide can be decreased when combined with Methimazole. Metolazone Metolazone may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Metoprolol The excretion of Metoprolol can be decreased when combined with Methimazole. Metronidazole The metabolism of Metronidazole can be decreased when combined with Methimazole. Metyrapone Methimazole may decrease the excretion rate of Metyrapone which could result in a higher serum level. Mexiletine The metabolism of Mexiletine can be decreased when combined with Methimazole. Mianserin The metabolism of Mianserin can be decreased when combined with Methimazole. Midazolam The serum concentration of Midazolam can be increased when it is combined with Methimazole. Midodrine The risk or severity of adverse effects can be increased when Midodrine is combined with Methimazole. Midostaurin The metabolism of Midostaurin can be decreased when combined with Methimazole. Mifepristone The metabolism of Mifepristone can be decreased when combined with Methimazole. Migalastat Methimazole may decrease the excretion rate of Migalastat which could result in a higher serum level. Milnacipran The metabolism of Milnacipran can be decreased when combined with Methimazole. Milrinone Milrinone may decrease the excretion rate of Methimazole which could result in a higher serum level. Minaprine The metabolism of Minaprine can be decreased when combined with Methimazole. Mirabegron The metabolism of Mirabegron can be decreased when combined with Methimazole. Mirtazapine The metabolism of Mirtazapine can be decreased when combined with Methimazole. Mirvetuximab The serum concentration of Mirvetuximab Soravtansine can be increased when it is combined with Methimazole. Mitapivat The metabolism of Mitapivat can be decreased when combined with Methimazole. Mitomycin The risk or severity of adverse effects can be increased when Mitomycin is combined with Methimazole. Mitoxantrone The risk or severity of adverse effects can be increased when Methimazole is combined with Mitoxantrone. Mobocertinib The serum concentration of Mobocertinib can be increased when it is combined with Methimazole. Moclobemide The metabolism of Moclobemide can be decreased when combined with Methimazole. Modafinil The metabolism of Modafinil can be decreased when combined with Methimazole. Moderna COVID-19 Vaccine The therapeutic efficacy of Moderna COVID-19 Vaccine can be decreased when used in combination with Methimazole. Modified vaccinia ankara The therapeutic efficacy of Modified vaccinia ankara can be decreased when used in combination with Methimazole. Mometasone furoate The metabolism of Mometasone furoate can be decreased when combined with Methimazole. Monomethyl fumarate The risk or severity of adverse effects can be increased when Methimazole is combined with Monomethyl fumarate. Montelukast The metabolism of Montelukast can be decreased when combined with Methimazole. Morphine The metabolism of Morphine can be decreased when combined with Methimazole. Mosunetuzumab The risk or severity of adverse effects can be increased when Methimazole is combined with Mosunetuzumab. Moxisylyte Methimazole may decrease the excretion rate of Moxisylyte which could result in a higher serum level. Mumps virus strain The therapeutic efficacy of Mumps virus strain B level jeryl lynn live antigen can be decreased when used in combination with Methimazole. Muromonab The risk or severity of adverse effects can be increased when Muromonab is combined with Methimazole. Muzolimine Muzolimine may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Mycophenolate mofetil The metabolism of Mycophenolate mofetil can be decreased when combined with Methimazole. Mycophenolic acid The risk or severity of adverse effects can be increased when Methimazole is combined with Mycophenolic acid. N-acetyltyrosine Methimazole may decrease the excretion rate of N-acetyltyrosine which could result in a higher serum level. Nabilone The metabolism of Nabilone can be decreased when combined with Methimazole. Nabumetone The metabolism of Nabumetone can be decreased when combined with Methimazole. Nadolol The excretion of Nadolol can be decreased when combined with Methimazole. Nadroparin Methimazole may increase the anticoagulant activities of Nadroparin. Naldemedine Methimazole may decrease the excretion rate of Naldemedine which could result in a higher serum level. Nalmefene Methimazole may decrease the excretion rate of Nalmefene which could result in a higher serum level. Naloxegol The metabolism of Naloxegol can be decreased when combined with Methimazole. Naloxone Methimazole may decrease the excretion rate of Naloxone which could result in a higher serum level. Naphazoline The risk or severity of adverse effects can be increased when Naphazoline is combined with Methimazole. Naproxen The metabolism of Naproxen can be decreased when combined with Methimazole. Natalizumab The risk or severity of immunosuppression can be increased when Methimazole is combined with Natalizumab. Nateglinide The metabolism of Nateglinide can be decreased when combined with Methimazole. Nebivolol The excretion of Nebivolol can be decreased when combined with Methimazole. Nedaplatin Methimazole may decrease the excretion rate of Nedaplatin which could result in a higher serum level. Nedocromil Nedocromil may decrease the excretion rate of Methimazole which could result in a higher serum level. Nefazodone The metabolism of Nefazodone can be decreased when combined with Methimazole. Nelarabine The risk or severity of adverse effects can be increased when Methimazole is combined with Nelarabine. Nelfinavir The metabolism of Nelfinavir can be decreased when combined with Methimazole. Neomycin Methimazole may decrease the excretion rate of Neomycin which could result in a higher serum level. Neratinib The serum concentration of Neratinib can be increased when it is combined with Methimazole. Netilmicin Methimazole may decrease the excretion rate of Netilmicin which could result in a higher serum level. Netupitant The metabolism of Netupitant can be decreased when combined with Methimazole. Nevirapine The metabolism of Nevirapine can be decreased when combined with Methimazole. Nicardipine The metabolism of Nicardipine can be decreased when combined with Methimazole. Nicergoline The serum concentration of Nicergoline can be increased when it is combined with Methimazole. Niclosamide The metabolism of Niclosamide can be decreased when combined with Methimazole. Nicorandil Methimazole may decrease the excretion rate of Nicorandil which could result in a higher serum level. Nicotine The metabolism of Nicotine can be decreased when combined with Methimazole. Nifedipine The metabolism of Nifedipine can be decreased when combined with Methimazole. Nilotinib The metabolism of Nilotinib can be decreased when combined with Methimazole. Nilutamide The metabolism of Nilutamide can be decreased when combined with Methimazole. Nilvadipine The metabolism of Nilvadipine can be decreased when combined with Methimazole. Nimesulide The metabolism of Nimesulide can be decreased when combined with Methimazole. Nimodipine The metabolism of Nimodipine can be decreased when combined with Methimazole. Nintedanib The metabolism of Nintedanib can be decreased when combined with Methimazole. Nirmatrelvir The metabolism of Nirmatrelvir can be decreased when combined with Methimazole. Nisoldipine The metabolism of Nisoldipine can be decreased when combined with Methimazole. Nitrazepam The metabolism of Nitrazepam can be decreased when combined with Methimazole. Nitrendipine The metabolism of Nitrendipine can be decreased when combined with Methimazole. Nitric Oxide Nitric Oxide may decrease the excretion rate of Methimazole which could result in a higher serum level. Nitrofurantoin Nitrofurantoin may decrease the excretion rate of Methimazole which could result in a higher serum level. Nitroprusside Nitroprusside may decrease the excretion rate of Methimazole which could result in a higher serum level. Nomegestrol The metabolism of Nomegestrol can be decreased when combined with Methimazole. Nomegestrol acetate The metabolism of Nomegestrol acetate can be decreased when combined with Methimazole. Norelgestromin The metabolism of Norelgestromin can be decreased when combined with Methimazole. Norepinephrine The risk or severity of adverse effects can be increased when Norepinephrine is combined with Methimazole. Norethisterone The metabolism of Norethisterone can be decreased when combined with Methimazole. Norethynodrel The metabolism of Norethynodrel can be decreased when combined with Methimazole. Norgestimate The metabolism of Norgestimate can be decreased when combined with Methimazole. Norgestrel The metabolism of Norgestrel can be decreased when combined with Methimazole. Nortriptyline The metabolism of Nortriptyline can be decreased when combined with Methimazole. Nuvaxovid The therapeutic efficacy of Nuvaxovid can be decreased when used in combination with Methimazole. Nylidrin The metabolism of Nylidrin can be decreased when combined with Methimazole. Obinutuzumab The risk or severity of adverse effects can be increased when Methimazole is combined with Obinutuzumab. Ocrelizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Ocrelizumab. Octinoxate Methimazole may decrease the excretion rate of Octinoxate which could result in a higher serum level. Ofatumumab The risk or severity of adverse effects can be increased when Methimazole is combined with Ofatumumab. Olanzapine The metabolism of Olanzapine can be decreased when combined with Methimazole. Olaparib The metabolism of Olaparib can be decreased when combined with Methimazole. Oliceridine The serum concentration of Oliceridine can be increased when it is combined with Methimazole. Olodaterol The metabolism of Olodaterol can be decreased when combined with Methimazole. Olsalazine Olsalazine may decrease the excretion rate of Methimazole which could result in a higher serum level. Olutasidenib The metabolism of Olutasidenib can be decreased when combined with Methimazole. Omaveloxolone The serum concentration of Omaveloxolone can be increased when it is combined with Methimazole. Omeprazole The metabolism of Omeprazole can be decreased when combined with Methimazole. Ondansetron The metabolism of Ondansetron can be decreased when combined with Methimazole. Opium The metabolism of Opium can be decreased when combined with Methimazole. Orciprenaline The risk or severity of adverse effects can be increased when Orciprenaline is combined with Methimazole. Orphenadrine The metabolism of Orphenadrine can be decreased when combined with Methimazole. Oseltamivir Oseltamivir may decrease the excretion rate of Methimazole which could result in a higher serum level. Osilodrostat The serum concentration of Osilodrostat can be increased when it is combined with Methimazole. Osimertinib The metabolism of Osimertinib can be decreased when combined with Methimazole. Ospemifene The metabolism of Ospemifene can be decreased when combined with Methimazole. Ouabain The serum concentration of Ouabain can be increased when it is combined with Methimazole. Oxacillin Oxacillin may decrease the excretion rate of Methimazole which could result in a higher serum level. Oxaliplatin The risk or severity of adverse effects can be increased when Oxaliplatin is combined with Methimazole. Oxaprozin Oxaprozin may decrease the excretion rate of Methimazole which could result in a higher serum level. Oxazepam Methimazole may decrease the excretion rate of Oxazepam which could result in a higher serum level. Oxprenolol The excretion of Oxprenolol can be decreased when combined with Methimazole. Oxtriphylline Methimazole may decrease the excretion rate of Oxtriphylline which could result in a higher serum level. Oxybenzone Methimazole may decrease the excretion rate of Oxybenzone which could result in a higher serum level. Oxybutynin The metabolism of Oxybutynin can be decreased when combined with Methimazole. Oxycodone The metabolism of Oxycodone can be decreased when combined with Methimazole. Oxymetazoline The risk or severity of adverse effects can be increased when Oxymetazoline is combined with Methimazole. Oxymorphone The metabolism of Oxymorphone can be decreased when combined with Methimazole. Oxyphenbutazone Oxyphenbutazone may decrease the excretion rate of Methimazole which could result in a higher serum level. Oxyquinoline Methimazole may decrease the excretion rate of Oxyquinoline which could result in a higher serum level. Ozanimod The risk or severity of adverse effects can be increased when Methimazole is combined with Ozanimod. Paclitaxel The metabolism of Paclitaxel can be decreased when combined with Methimazole. Pacritinib The serum concentration of Pacritinib can be increased when it is combined with Methimazole. Palbociclib The metabolism of Palbociclib can be decreased when combined with Methimazole. Palifermin The therapeutic efficacy of Palifermin can be decreased when used in combination with Methimazole. Paliperidone The metabolism of Paliperidone can be decreased when combined with Methimazole. Palonosetron The metabolism of Palonosetron can be decreased when combined with Methimazole. Palovarotene The serum concentration of Palovarotene can be increased when it is combined with Methimazole. Pamidronic acid Pamidronic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Panobinostat The metabolism of Panobinostat can be decreased when combined with Methimazole. Pantoprazole The metabolism of Pantoprazole can be decreased when combined with Methimazole. Paramethadione The metabolism of Paramethadione can be decreased when combined with Methimazole. Parecoxib The metabolism of Parecoxib can be decreased when combined with Methimazole. Paricalcitol The metabolism of Paricalcitol can be decreased when combined with Methimazole. Paritaprevir The metabolism of Paritaprevir can be decreased when combined with Methimazole. Parnaparin Methimazole may increase the anticoagulant activities of Parnaparin. Paromomycin Paromomycin may decrease the excretion rate of Methimazole which could result in a higher serum level. Paroxetine The metabolism of Paroxetine can be decreased when combined with Methimazole. Patent Blue Methimazole may decrease the excretion rate of Patent Blue which could result in a higher serum level. Pazopanib The metabolism of Pazopanib can be decreased when combined with Methimazole. Pegaptanib Methimazole may decrease the excretion rate of Pegaptanib which could result in a higher serum level. Pegaspargase The risk or severity of adverse effects can be increased when Pegaspargase is combined with Methimazole. Pegcetacoplan The risk or severity of adverse effects can be increased when Methimazole is combined with Pegcetacoplan. Peginesatide Methimazole may decrease the excretion rate of Peginesatide which could result in a higher serum level. Peginterferon alfa-2a The risk or severity of adverse effects can be increased when Peginterferon alfa-2a is combined with Methimazole. Peginterferon alfa-2b The risk or severity of adverse effects can be increased when Peginterferon alfa-2b is combined with Methimazole. Peginterferon beta-1a The risk or severity of adverse effects can be increased when Methimazole is combined with Peginterferon beta-1a. Pemetrexed The risk or severity of adverse effects can be increased when Pemetrexed is combined with Methimazole. Pemigatinib The metabolism of Pemigatinib can be decreased when combined with Methimazole. Penbutolol The excretion of Penbutolol can be decreased when combined with Methimazole. Penciclovir The metabolism of Penciclovir can be decreased when combined with Methimazole. Penicillamine The risk or severity of adverse effects can be increased when Methimazole is combined with Penicillamine. Pentaerythritol tetranitrate Methimazole may decrease the excretion rate of Pentaerythritol tetranitrate which could result in a higher serum level. Pentamidine The metabolism of Pentamidine can be decreased when combined with Methimazole. Pentastarch Methimazole may decrease the excretion rate of Pentastarch which could result in a higher serum level. Pentetic acid Methimazole may decrease the excretion rate of Pentetic acid which could result in a higher serum level. Pentobarbital The metabolism of Pentobarbital can be decreased when combined with Methimazole. Pentosan polysulfate Methimazole may increase the anticoagulant activities of Pentosan polysulfate. Pentostatin The risk or severity of adverse effects can be increased when Pentostatin is combined with Methimazole. Pentoxifylline Methimazole may decrease the excretion rate of Pentoxifylline which could result in a higher serum level. Perampanel The metabolism of Perampanel can be decreased when combined with Methimazole. Pergolide The serum concentration of Pergolide can be increased when it is combined with Methimazole. Perhexiline The metabolism of Perhexiline can be decreased when combined with Methimazole. Perindopril Methimazole may decrease the excretion rate of Perindopril which could result in a higher serum level. Permethrin Methimazole may decrease the excretion rate of Permethrin which could result in a higher serum level. Perphenazine The metabolism of Perphenazine can be decreased when combined with Methimazole. Pertussis vaccine The therapeutic efficacy of Pertussis vaccine can be decreased when used in combination with Methimazole. Pexidartinib The metabolism of Pexidartinib can be decreased when combined with Methimazole. Phenazopyridine Phenazopyridine may decrease the excretion rate of Methimazole which could result in a higher serum level. Phenelzine Methimazole may decrease the excretion rate of Phenelzine which could result in a higher serum level. Phenformin The metabolism of Phenformin can be decreased when combined with Methimazole. Phenindione Methimazole may decrease the anticoagulant activities of Phenindione. Phenmetrazine The risk or severity of adverse effects can be increased when Phenmetrazine is combined with Methimazole. Phenobarbital The metabolism of Phenobarbital can be decreased when combined with Methimazole. Phenprocoumon Methimazole may decrease the anticoagulant activities of Phenprocoumon. Phentermine The metabolism of Phentermine can be decreased when combined with Methimazole. Phenylalanine The risk or severity of adverse effects can be increased when Phenylalanine is combined with Methimazole. Phenylbutazone The metabolism of Phenylbutazone can be decreased when combined with Methimazole. Phenylephrine The risk or severity of adverse effects can be increased when Phenylephrine is combined with Methimazole. Phenylpropanolamine The risk or severity of adverse effects can be increased when Phenylpropanolamine is combined with Methimazole. Phenytoin The metabolism of Phenytoin can be decreased when combined with Methimazole. Pholcodine Methimazole may decrease the excretion rate of Pholcodine which could result in a higher serum level. Phosphoric acid Methimazole may decrease the excretion rate of Phosphoric acid which could result in a higher serum level. Phylloquinone Methimazole may decrease the excretion rate of Phylloquinone which could result in a higher serum level. Picosulfuric acid Methimazole may decrease the excretion rate of Picosulfuric acid which could result in a higher serum level. Pimavanserin The metabolism of Pimavanserin can be decreased when combined with Methimazole. Pimecrolimus The risk or severity of adverse effects can be increased when Pimecrolimus is combined with Methimazole. Pimozide The metabolism of Pimozide can be decreased when combined with Methimazole. Pinacidil The metabolism of Pinacidil can be decreased when combined with Methimazole. Pinaverium The metabolism of Pinaverium can be decreased when combined with Methimazole. Pindolol The excretion of Pindolol can be decreased when combined with Methimazole. Pioglitazone The metabolism of Pioglitazone can be decreased when combined with Methimazole. Piperacillin Piperacillin may decrease the excretion rate of Methimazole which could result in a higher serum level. Piperaquine The metabolism of Piperaquine can be decreased when combined with Methimazole. Piperazine The metabolism of Piperazine can be decreased when combined with Methimazole. Pipotiazine The metabolism of Pipotiazine can be decreased when combined with Methimazole. Piracetam Methimazole may decrease the excretion rate of Piracetam which could result in a higher serum level. Piretanide Piretanide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Pirfenidone The risk or severity of adverse effects can be increased when Methimazole is combined with Pirfenidone. Piroxicam The metabolism of Piroxicam can be decreased when combined with Methimazole. Pirtobrutinib The serum concentration of Pirtobrutinib can be increased when it is combined with Methimazole. Pitavastatin The metabolism of Pitavastatin can be decreased when combined with Methimazole. Pitolisant The metabolism of Pitolisant can be decreased when combined with Methimazole. Plazomicin Methimazole may decrease the excretion rate of Plazomicin which could result in a higher serum level. Plerixafor Methimazole may decrease the excretion rate of Plerixafor which could result in a higher serum level. Polatuzumab vedo The risk or severity of adverse effects can be increased when Methimazole is combined with Polatuzumab vedotin. Polythiazide Polythiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Pomalidomide The metabolism of Pomalidomide can be decreased when combined with Methimazole. Ponatinib The metabolism of Ponatinib can be decreased when combined with Methimazole. Ponesimod The metabolism of Ponesimod can be decreased when combined with Methimazole. Posaconazole The metabolism of Posaconazole can be decreased when combined with Methimazole. Potassium Potassium may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Potassium acetate Methimazole may decrease the excretion rate of Potassium acetate which could result in a higher serum level. Potassium bicarbonate Methimazole may decrease the excretion rate of Potassium bicarbonate which could result in a higher serum level. Potassium cation Potassium cation may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Potassium chloride Potassium chloride may decrease the excretion rate of Methimazole which could result in a higher serum level. Potassium citrate Potassium citrate may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Potassium nitrate Methimazole may decrease the excretion rate of Potassium nitrate which could result in a higher serum level. Potassium perchlorate Methimazole may decrease the excretion rate of Potassium perchlorate which could result in a higher serum level. Potassium sulfate Methimazole may decrease the excretion rate of Potassium sulfate which could result in a higher serum level. Practolol The excretion of Practolol can be decreased when combined with Methimazole. Pralatrexate The risk or severity of adverse effects can be increased when Methimazole is combined with Pralatrexate. Pralidoxime Pralidoxime may decrease the excretion rate of Methimazole which could result in a higher serum level. Pralsetinib The serum concentration of Pralsetinib can be increased when it is combined with Methimazole. Pramipexole Pramipexole may decrease the excretion rate of Methimazole which could result in a higher serum level. Prasugrel The metabolism of Prasugrel can be decreased when combined with Methimazole. Prazepam The metabolism of Prazepam can be decreased when combined with Methimazole. Praziquantel The metabolism of Praziquantel can be decreased when combined with Methimazole. Prednisolone Methimazole may increase the excretion rate of Prednisolone which could result in a lower serum level and potentially a reduction in efficacy. Prednisolone acetate The metabolism of Prednisolone acetate can be decreased when combined with Methimazole. Prednisolone phosphate The metabolism of Prednisolone phosphate can be decreased when combined with Methimazole. Prednisone Methimazole may increase the excretion rate of Prednisone which could result in a lower serum level and potentially a reduction in efficacy. Pregabalin Pregabalin may decrease the excretion rate of Methimazole which could result in a higher serum level. Pregnenolone The metabolism of Pregnenolone can be decreased when combined with Methimazole. Prenylamine The metabolism of Prenylamine can be decreased when combined with Methimazole. Pretomanid The metabolism of Pretomanid can be decreased when combined with Methimazole. Primaquine The metabolism of Primaquine can be decreased when combined with Methimazole. Primidone The metabolism of Primidone can be decreased when combined with Methimazole. Probenecid Methimazole may decrease the excretion rate of Probenecid which could result in a higher serum level. Procainamide The metabolism of Procainamide can be decreased when combined with Methimazole. Procaine benzylpenicillin Methimazole may decrease the excretion rate of Procaine benzylpenicillin which could result in a higher serum level. Procarbazine The risk or severity of adverse effects can be increased when Methimazole is combined with Procarbazine. Procaterol The risk or severity of adverse effects can be increased when Procaterol is combined with Methimazole. Prochlorperazine The metabolism of Prochlorperazine can be decreased when combined with Methimazole. Progesterone The metabolism of Progesterone can be decreased when combined with Methimazole. Proguanil The metabolism of Proguanil can be decreased when combined with Methimazole. Promazine The metabolism of Promazine can be decreased when combined with Methimazole. Promethazine The metabolism of Promethazine can be decreased when combined with Methimazole. Propafenone The excretion of Propafenone can be decreased when combined with Methimazole. Propantheline Methimazole may decrease the excretion rate of Propantheline which could result in a higher serum level. Propiverine The metabolism of Propiverine can be decreased when combined with Methimazole. Propofol The metabolism of Propofol can be decreased when combined with Methimazole. Propranolol The excretion of Propranolol can be decreased when combined with Methimazole. Propylthiouracil The risk or severity of adverse effects can be increased when Propylthiouracil is combined with Methimazole. Protein C Methimazole may increase the anticoagulant activities of Protein C. Protein S human Methimazole may increase the anticoagulant activities of Protein S human. Protriptyline The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Protriptyline. Prucalopride The metabolism of Prucalopride can be decreased when combined with Methimazole. Pseudoephedrine The risk or severity of adverse effects can be increased when Pseudoephedrine is combined with Methimazole. Pyrantel Methimazole may decrease the excretion rate of Pyrantel which could result in a higher serum level. Pyrazinamide Pyrazinamide may decrease the excretion rate of Methimazole which could result in a higher serum level. Pyridoxine Pyridoxine may decrease the excretion rate of Methimazole which could result in a higher serum level. Quazepam The metabolism of Quazepam can be decreased when combined with Methimazole. Quetiapine The serum concentration of Quetiapine can be increased when it is combined with Methimazole. Quinethazone Quinethazone may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Quinidine The metabolism of Quinidine can be decreased when combined with Methimazole. Quinine The metabolism of Quinine can be decreased when combined with Methimazole. Quinupramine The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Quinupramine. Quizartinib The serum concentration of Quizartinib can be increased when it is combined with Methimazole. Rabeprazole The metabolism of Rabeprazole can be decreased when combined with Methimazole. Rabies immune globulin, human The therapeutic efficacy of Rabies immune globulin, human can be decreased when used in combination with Methimazole. Rabies virus inactivated antigen, A The therapeutic efficacy of Rabies virus inactivated antigen, A can be decreased when used in combination with Methimazole. Rabies virus The therapeutic efficacy of Rabies virus inactivated antigen, B can be decreased when used in combination with Methimazole. Racepinephrine The risk or severity of adverse effects can be increased when Racepinephrine is combined with Methimazole. Raltitrexed The risk or severity of adverse effects can be increased when Raltitrexed is combined with Methimazole. Ramelteon The metabolism of Ramelteon can be decreased when combined with Methimazole. Ranitidine The metabolism of Ranitidine can be decreased when combined with Methimazole. Ranolazine The metabolism of Ranolazine can be decreased when combined with Methimazole. Rasagiline The metabolism of Rasagiline can be decreased when combined with Methimazole. Ravulizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Ravulizumab. Reboxetine The metabolism of Reboxetine can be decreased when combined with Methimazole. Regorafenib The metabolism of Regorafenib can be decreased when combined with Methimazole. Relugolix The metabolism of Relugolix can be decreased when combined with Methimazole. Remdesivir The metabolism of Remdesivir can be decreased when combined with Methimazole. Remoxipride The metabolism of Remoxipride can be decreased when combined with Methimazole. Repaglinide The metabolism of Repaglinide can be decreased when combined with Methimazole. Reserpine Reserpine may decrease the excretion rate of Methimazole which could result in a higher serum level. Resorcinol The therapeutic efficacy of Methimazole can be decreased when used in combination with Resorcinol. Retapamulin The metabolism of Retapamulin can be decreased when combined with Methimazole. Reteplase Methimazole may increase the anticoagulant activities of Reteplase. Revefenacin The metabolism of Revefenacin can be decreased when combined with Methimazole. Reviparin Methimazole may increase the anticoagulant activities of Reviparin. Ribavirin Methimazole may decrease the excretion rate of Ribavirin which could result in a higher serum level. Ribociclib The metabolism of Ribociclib can be decreased when combined with Methimazole. Ribostamycin Methimazole may decrease the excretion rate of Ribostamycin which could result in a higher serum level. Rifabutin The metabolism of Rifabutin can be decreased when combined with Methimazole. Rifapentine The metabolism of Rifapentine can be decreased when combined with Methimazole. Rilonacept The risk or severity of adverse effects can be increased when Methimazole is combined with Rilonacept. Rilpivirine The metabolism of Rilpivirine can be decreased when combined with Methimazole. Riluzole The metabolism of Riluzole can be decreased when combined with Methimazole. Rimegepant The metabolism of Rimegepant can be decreased when combined with Methimazole. Rimonabant The metabolism of Rimonabant can be decreased when combined with Methimazole. Riociguat The serum concentration of Riociguat can be increased when it is combined with Methimazole. Ripretinib The serum concentration of Ripretinib can be increased when it is combined with Methimazole. Risankizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Risankizumab. Risperidone The metabolism of Risperidone can be decreased when combined with Methimazole. Ritodrine The risk or severity of adverse effects can be increased when Ritodrine is combined with Methimazole. Ritonavir The metabolism of Ritonavir can be decreased when combined with Methimazole. Rituximab The risk or severity of adverse effects can be increased when Rituximab is combined with Methimazole. Rivaroxaban The metabolism of Rivaroxaban can be decreased when combined with Methimazole. Rizatriptan Methimazole may decrease the excretion rate of Rizatriptan which could result in a higher serum level. Rofecoxib The metabolism of Rofecoxib can be decreased when combined with Methimazole. Roflumilast The serum concentration of Roflumilast can be increased when it is combined with Methimazole. Rolapitant The metabolism of Rolapitant can be decreased when combined with Methimazole. Romidepsin The metabolism of Romidepsin can be decreased when combined with Methimazole. Ropeginterfero The risk or severity of adverse effects can be increased when Methimazole is combined with Ropeginterferon alfa-2b. Ropinirole The risk or severity of adverse effects can be increased when Methimazole is combined with Ropinirole. Ropivacaine The metabolism of Ropivacaine can be decreased when combined with Methimazole. Rosiglitazone The metabolism of Rosiglitazone can be decreased when combined with Methimazole. Rosuvastatin The metabolism of Rosuvastatin can be decreased when combined with Methimazole. Rotavirus vaccine The therapeutic efficacy of Rotavirus vaccine can be decreased when used in combination with Methimazole. Rotigotine The metabolism of Rotigotine can be decreased when combined with Methimazole. Roxithromycin The metabolism of Roxithromycin can be decreased when combined with Methimazole. Rozanolixizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Rozanolixizumab. Rubella virus vaccine The risk or severity of infection can be increased when Rubella virus vaccine is combined with Methimazole. Rucaparib The metabolism of Rucaparib can be decreased when combined with Methimazole. Rupatadine The metabolism of Rupatadine can be decreased when combined with Methimazole. Ruxolitinib The metabolism of Ruxolitinib can be decreased when combined with Methimazole. Sacubitril Methimazole may decrease the excretion rate of Sacubitril which could result in a higher serum level. Safinamide The metabolism of Safinamide can be decreased when combined with Methimazole. Salbutamol Methimazole may decrease the excretion rate of Salbutamol which could result in a higher serum level. Salicylamide Salicylamide may decrease the excretion rate of Methimazole which could result in a higher serum level. Salicylic acid The metabolism of Salicylic acid can be decreased when combined with Methimazole. Salmeterol The metabolism of Salmeterol can be decreased when combined with Methimazole. Salmon calcitonin Salmon calcitonin may decrease the excretion rate of Methimazole which could result in a higher serum level. Salsalate Salsalate may decrease the excretion rate of Methimazole which could result in a higher serum level. Samidorphan The metabolism of Samidorphan can be decreased when combined with Methimazole. Saquinavir The metabolism of Saquinavir can be decreased when combined with Methimazole. Sarilumab The risk or severity of adverse effects can be increased when Methimazole is combined with Sarilumab. Satralizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Satralizumab. Saxagliptin The metabolism of Saxagliptin can be decreased when combined with Methimazole. Scopolamine The metabolism of Scopolamine can be decreased when combined with Methimazole. Secobarbital Secobarbital may decrease the excretion rate of Methimazole which could result in a higher serum level. Secukinumab The risk or severity of adverse effects can be increased when Methimazole is combined with Secukinumab. Selegiline The metabolism of Selegiline can be decreased when combined with Methimazole. Selenious acid Methimazole may decrease the excretion rate of Selenious acid which could result in a higher serum level. Selenium Methimazole may decrease the excretion rate of Selenium which could result in a higher serum level. Selexipag The metabolism of Selexipag can be decreased when combined with Methimazole. Selinexor The metabolism of Selinexor can be decreased when combined with Methimazole. Selpercatinib The metabolism of Selpercatinib can be decreased when combined with Methimazole. Selumetinib The serum concentration of Selumetinib can be increased when it is combined with Methimazole. Sertindole The metabolism of Sertindole can be decreased when combined with Methimazole. Sertraline The metabolism of Sertraline can be decreased when combined with Methimazole. Sevoflurane The metabolism of Sevoflurane can be decreased when combined with Methimazole. Sibutramine The metabolism of Sibutramine can be decreased when combined with Methimazole. Sildenafil The metabolism of Sildenafil can be decreased when combined with Methimazole. Silodosin The metabolism of Silodosin can be decreased when combined with Methimazole. Siltuximab The risk or severity of adverse effects can be increased when Methimazole is combined with Siltuximab. Simeprevir The metabolism of Simeprevir can be decreased when combined with Methimazole. Simvastatin The risk or severity of myopathy and rhabdomyolysis can be increased when Methimazole is combined with Simvastatin. Siponimod The risk or severity of adverse effects can be increased when Methimazole is combined with Siponimod. Sipuleucel-T The therapeutic efficacy of Sipuleucel-T can be decreased when used in combination with Methimazole. Sirolimus The metabolism of Sirolimus can be decreased when combined with Methimazole. Sitagliptin The metabolism of Sitagliptin can be decreased when combined with Methimazole. Sitaxentan The metabolism of Sitaxentan can be decreased when combined with Methimazole. Smallpox The therapeutic efficacy of Smallpox (Vaccinia) Vaccine, Live can be decreased when used in combination with Methimazole. Sodium acetate Methimazole may decrease the excretion rate of Sodium acetate which could result in a higher serum level. Sodium aurothiomalate Methimazole may decrease the excretion rate of Sodium aurothiomalate which could result in a higher serum level. Sodium citrate Methimazole may increase the anticoagulant activities of Sodium citrate. Sodium fluoride Methimazole may decrease the excretion rate of Sodium fluoride which could result in a higher serum level. Sodium sulfate Methimazole may decrease the excretion rate of Sodium sulfate which could result in a higher serum level. Sofosbuvir Methimazole may decrease the excretion rate of Sofosbuvir which could result in a higher serum level. Solifenacin The metabolism of Solifenacin can be decreased when combined with Methimazole. Solriamfetol Methimazole may decrease the excretion rate of Solriamfetol which could result in a higher serum level. Sonidegib The metabolism of Sonidegib can be decreased when combined with Methimazole. Sorafenib The metabolism of Sorafenib can be decreased when combined with Methimazole. Sorbitol Methimazole may decrease the excretion rate of Sorbitol which could result in a higher serum level. Sotalol The excretion of Sotalol can be decreased when combined with Methimazole. Sparsentan The serum concentration of Sparsentan can be increased when it is combined with Methimazole. Spesolimab The risk or severity of adverse effects can be increased when Methimazole is combined with Spesolimab. Spironolactone Spironolactone may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. St. John's Wort The metabolism of St. John's Wort can be decreased when combined with Methimazole. Stiripentol The metabolism of Methimazole can be decreased when combined with Stiripentol. Streptokinase Methimazole may increase the anticoagulant activities of Streptokinase. Streptomycin Methimazole may decrease the excretion rate of Streptomycin which could result in a higher serum level. Streptozocin The risk or severity of adverse effects can be increased when Streptozocin is combined with Methimazole. Strontium chloride Methimazole may decrease the excretion rate of Strontium chloride which could result in a higher serum level. Sucralfate Sucralfate may decrease the excretion rate of Methimazole which could result in a higher serum level. Sufentanil The metabolism of Sufentanil can be decreased when combined with Methimazole. Sulbactam Methimazole may decrease the excretion rate of Sulbactam which could result in a higher serum level. Sulfadiazine The metabolism of Sulfadiazine can be decreased when combined with Methimazole. Sulfamethoxazole The risk or severity of myelosuppression can be increased when Sulfamethoxazole is combined with Methimazole. Sulfasalazine The risk or severity of adverse effects can be increased when Methimazole is combined with Sulfasalazine. Sulfinpyrazone The metabolism of Sulfinpyrazone can be decreased when combined with Methimazole. Sulindac Sulindac may decrease the excretion rate of Methimazole which could result in a higher serum level. Sulodexide Methimazole may increase the anticoagulant activities of Sulodexide. Sumatriptan Sumatriptan may decrease the excretion rate of Methimazole which could result in a higher serum level. Sunitinib The metabolism of Sunitinib can be decreased when combined with Methimazole. Sutimlimab The risk or severity of adverse effects can be increased when Methimazole is combined with Sutimlimab. Suvorexant The metabolism of Suvorexant can be decreased when combined with Methimazole. Synthetic Conju The metabolism of Synthetic Conjugated Estrogens, A can be decreased when combined with Methimazole. Synthetic Con The metabolism of Synthetic Conjugated Estrogens, B can be decreased when combined with Methimazole. Tacrine The metabolism of Tacrine can be decreased when combined with Methimazole. Tacrolimus The serum concentration of Tacrolimus can be increased when it is combined with Methimazole. Tadalafil The serum concentration of Tadalafil can be increased when it is combined with Methimazole. Tafenoquine The metabolism of Tafenoquine can be decreased when combined with Methimazole. Tamoxifen The metabolism of Tamoxifen can be decreased when combined with Methimazole. Tamsulosin The metabolism of Tamsulosin can be decreased when combined with Methimazole. Tasimelteon The metabolism of Tasimelteon can be decreased when combined with Methimazole. Tazemetostat The metabolism of Tazemetostat can be decreased when combined with Methimazole. Technetium T Methimazole may decrease the excretion rate of Technetium Tc-99m exametazime which could result in a higher serum level. Technetium Tc-9 Methimazole may decrease the excretion rate of Technetium Tc-99m mebrofenin which could result in a higher serum level. Technetium Tc-9 Methimazole may decrease the excretion rate of Technetium Tc-99m oxidronate which could result in a higher serum level. Technetium Tc-99 Methimazole may decrease the excretion rate of Technetium Tc-99m pyrophosphate which could result in a higher serum level. Tedizolid phosphate The risk or severity of myelosuppression can be increased when Methimazole is combined with Tedizolid phosphate. Teduglutide Methimazole may decrease the excretion rate of Teduglutide which could result in a higher serum level. Tegafur The metabolism of Tegafur can be decreased when combined with Methimazole. Tegafur-uracil The metabolism of Tegafur-uracil can be decreased when combined with Methimazole. Tegaserod The metabolism of Tegaserod can be decreased when combined with Methimazole. Telaprevir The metabolism of Telaprevir can be decreased when combined with Methimazole. Telavancin Methimazole may decrease the excretion rate of Telavancin which could result in a higher serum level. Telithromycin The metabolism of Telithromycin can be decreased when combined with Methimazole. Temazepam Temazepam may decrease the excretion rate of Methimazole which could result in a higher serum level. Temozolomide The risk or severity of adverse effects can be increased when Methimazole is combined with Temozolomide. Temsirolimus The metabolism of Temsirolimus can be decreased when combined with Methimazole. Tenecteplase Methimazole may increase the anticoagulant activities of Tenecteplase. Teniposide The metabolism of Teniposide can be decreased when combined with Methimazole. Tenofovir alafenamide The serum concentration of Tenofovir alafenamide can be increased when it is combined with Methimazole. Tenofovir disoproxil Tenofovir disoproxil may decrease the excretion rate of Methimazole which could result in a higher serum level. Tenoxicam The metabolism of Tenoxicam can be decreased when combined with Methimazole. Tepotinib The serum concentration of Tepotinib can be increased when it is combined with Methimazole. Teprotumumab The risk or severity of adverse effects can be increased when Methimazole is combined with Teprotumumab. Terbinafine The metabolism of Terbinafine can be decreased when combined with Methimazole. Terbutaline The risk or severity of adverse effects can be increased when Terbutaline is combined with Methimazole. Terfenadine The metabolism of Terfenadine can be decreased when combined with Methimazole. Teriflunomide The risk or severity of adverse effects can be increased when Methimazole is combined with Teriflunomide. Testolactone Methimazole may decrease the excretion rate of Testolactone which could result in a higher serum level. Testosterone The metabolism of Testosterone can be decreased when combined with Methimazole. Testosterone cypionate The metabolism of Testosterone cypionate can be decreased when combined with Methimazole. Testosterone enanthate The metabolism of Testosterone enanthate can be decreased when combined with Methimazole. Testosterone propionate The metabolism of Testosterone propionate can be decreased when combined with Methimazole. Testosterone undecanoate Methimazole may decrease the excretion rate of Testosterone undecanoate which could result in a higher serum level. Tetrabenazine The metabolism of Tetrabenazine can be decreased when combined with Methimazole. Tetracycline The metabolism of Tetracycline can be decreased when combined with Methimazole. Tetradecyl hydrogen sulfa Methimazole may decrease the excretion rate of Tetradecyl hydrogen sulfate (ester) which could result in a higher serum level. Tetryzoline The risk or severity of adverse effects can be increased when Tetryzoline is combined with Methimazole. Tezacaftor The metabolism of Tezacaftor can be decreased when combined with Methimazole. Thalidomide The metabolism of Thalidomide can be decreased when combined with Methimazole. Theophylline The excretion of Theophylline can be decreased when combined with Methimazole. Thiabendazole The metabolism of Thiabendazole can be decreased when combined with Methimazole. Thiamylal The metabolism of Thiamylal can be decreased when combined with Methimazole. Thiethylperazine Thiethylperazine may decrease the excretion rate of Methimazole which could result in a higher serum level. Thiopental The metabolism of Thiopental can be decreased when combined with Methimazole. Thioridazine The metabolism of Thioridazine can be decreased when combined with Methimazole. Thiotepa The metabolism of Thiotepa can be decreased when combined with Methimazole. Thiothixene The metabolism of Thiothixene can be decreased when combined with Methimazole. Tiagabine The metabolism of Tiagabine can be decreased when combined with Methimazole. Tiaprofenic acid Tiaprofenic acid may decrease the excretion rate of Methimazole which could result in a higher serum level. Ticagrelor The metabolism of Ticagrelor can be decreased when combined with Methimazole. Tick-borne encephalitis The therapeutic efficacy of Tick-borne encephalitis vaccine (whole virus, inactivated) can be decreased when used in combination with Methimazole. Ticlopidine The metabolism of Ticlopidine can be decreased when combined with Methimazole. Tiludronic acid Methimazole may decrease the excretion rate of Tiludronic acid which could result in a higher serum level. Timolol The metabolism of Timolol can be decreased when combined with Methimazole. Tinidazole The metabolism of Tinidazole can be decreased when combined with Methimazole. Tinzaparin Methimazole may increase the anticoagulant activities of Tinzaparin. Tioguanine The risk or severity of adverse effects can be increased when Tioguanine is combined with Methimazole. Tiopronin Methimazole may decrease the excretion rate of Tiopronin which could result in a higher serum level. Tiotropium The metabolism of Tiotropium can be decreased when combined with Methimazole. Tipranavir The metabolism of Tipranavir can be decreased when combined with Methimazole. Tirofiban The risk or severity of bleeding can be increased when Tirofiban is combined with Methimazole. Tisotumab vedotin The metabolism of Tisotumab vedotin can be decreased when combined with Methimazole. Tivozanib The therapeutic efficacy of Methimazole can be decreased when used in combination with Tivozanib. Tixocortol The risk or severity of adverse effects can be increased when Methimazole is combined with Tixocortol. Tizanidine The metabolism of Tizanidine can be decreased when combined with Methimazole. Tobramycin Methimazole may decrease the excretion rate of Tobramycin which could result in a higher serum level. Tocainide The metabolism of Tocainide can be decreased when combined with Methimazole. Tocilizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Tocilizumab. Tocofersolan The metabolism of Tocofersolan can be decreased when combined with Methimazole. Tocopherol The metabolism of Tocopherol can be decreased when combined with Methimazole. Tofacitinib The metabolism of Tofacitinib can be decreased when combined with Methimazole. Tolazamide The therapeutic efficacy of Tolazamide can be decreased when used in combination with Methimazole. Tolbutamide The therapeutic efficacy of Tolbutamide can be decreased when used in combination with Methimazole. Tolcapone Tolcapone may decrease the excretion rate of Methimazole which could result in a higher serum level. Tolfenamic acid The metabolism of Tolfenamic acid can be decreased when combined with Methimazole. Tolmetin Tolmetin may decrease the excretion rate of Methimazole which could result in a higher serum level. Tolterodine The serum concentration of Tolterodine can be increased when it is combined with Methimazole. Tolvaptan The metabolism of Tolvaptan can be decreased when combined with Methimazole. Topiramate Topiramate may decrease the excretion rate of Methimazole which could result in a higher serum level. Topotecan The risk or severity of adverse effects can be increased when Methimazole is combined with Topotecan. Torasemide Torasemide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Toremifene The metabolism of Toremifene can be decreased when combined with Methimazole. Tositumomab The risk or severity of adverse effects can be increased when Tositumomab is combined with Methimazole. Trabectedin The metabolism of Trabectedin can be decreased when combined with Methimazole. Tramadol The metabolism of Tramadol can be decreased when combined with Methimazole. Trametinib Methimazole may decrease the excretion rate of Trametinib which could result in a higher serum level. Trastuzumab The risk or severity of neutropenia can be increased when Trastuzumab is combined with Methimazole. Trastuzumab emtansine The metabolism of Trastuzumab emtansine can be decreased when combined with Methimazole. Trazodone The serum concentration of Trazodone can be increased when it is combined with Methimazole. Treprostinil The metabolism of Treprostinil can be decreased when combined with Methimazole. Tretinoin The metabolism of Tretinoin can be decreased when combined with Methimazole. Triamcinolone The metabolism of Triamcinolone can be decreased when combined with Methimazole. Triamterene Triamterene may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Triazolam The metabolism of Triazolam can be decreased when combined with Methimazole. Trichlormethiazide Trichlormethiazide may increase the excretion rate of Methimazole which could result in a lower serum level and potentially a reduction in efficacy. Triclabendazole The metabolism of Triclabendazole can be decreased when combined with Methimazole. Triethylenetetramine Methimazole may decrease the excretion rate of Triethylenetetramine which could result in a higher serum level. Trifluoperazine The metabolism of Trifluoperazine can be decreased when combined with Methimazole. Trifluridine The risk or severity of adverse effects can be increased when Trifluridine is combined with Methimazole. Triflusal Methimazole may increase the anticoagulant activities of Triflusal. Trilostane The metabolism of Trilostane can be decreased when combined with Methimazole. Trimebutine The metabolism of Trimebutine can be decreased when combined with Methimazole. Trimethadione The metabolism of Trimethadione can be decreased when combined with Methimazole. Trimethoprim The metabolism of Trimethoprim can be decreased when combined with Methimazole. Trimetrexate Methimazole may decrease the excretion rate of Trimetrexate which could result in a higher serum level. Trimipramine The risk or severity of Cardiac Arrhythmia can be increased when Methimazole is combined with Trimipramine. Troglitazone The metabolism of Troglitazone can be decreased when combined with Methimazole. Troleandomycin The metabolism of Troleandomycin can be decreased when combined with Methimazole. Tropisetron Methimazole may decrease the excretion rate of Tropisetron which could result in a higher serum level. Tucatinib The therapeutic efficacy of Methimazole can be decreased when used in combination with Tucatinib. Typhoid vaccine The therapeutic efficacy of Typhoid vaccine can be decreased when used in combination with Methimazole. Typhoid Vaccine Live The risk or severity of infection can be increased when Typhoid Vaccine Live is combined with Methimazole. Typhoid Vi polysacc The therapeutic efficacy of Typhoid Vi polysaccharide vaccine can be decreased when used in combination with Methimazole. Ublituximab The risk or severity of infection can be increased when Ublituximab is combined with Methimazole. Ubrogepant The serum concentration of Ubrogepant can be increased when it is combined with Methimazole. Udenafil The metabolism of Udenafil can be decreased when combined with Methimazole. Ulipristal The metabolism of Ulipristal can be decreased when combined with Methimazole. Umeclidinium The metabolism of Umeclidinium can be decreased when combined with Methimazole. Upadacitinib The metabolism of Upadacitinib can be decreased when combined with Methimazole. Urokinase Methimazole may increase the anticoagulant activities of Urokinase. Vaborbactam Methimazole may decrease the excretion rate of Vaborbactam which could result in a higher serum level. Valaciclovir Valaciclovir may decrease the excretion rate of Methimazole which could result in a higher serum level. Valbenazine The serum concentration of Valbenazine can be increased when it is combined with Methimazole. Valdecoxib The metabolism of Valdecoxib can be decreased when combined with Methimazole. Valganciclovir Methimazole may decrease the excretion rate of Valganciclovir which could result in a higher serum level. Valproic acid The metabolism of Valproic acid can be decreased when combined with Methimazole. Valsartan The metabolism of Valsartan can be decreased when combined with Methimazole. Vancomycin Methimazole may decrease the excretion rate of Vancomycin which could result in a higher serum level. Vandetanib The metabolism of Vandetanib can be decreased when combined with Methimazole. Vardenafil The metabolism of Vardenafil can be decreased when combined with Methimazole. Varenicline Methimazole may decrease the excretion rate of Varenicline which could result in a higher serum level. Varicella zoster The risk or severity of infection can be increased when Varicella zoster vaccine (live/attenuated) is combined with Methimazole. Varicella zoster t) The therapeutic efficacy of Varicella zoster vaccine (recombinant) can be decreased when used in combination with Methimazole. Vedolizumab The risk or severity of adverse effects can be increased when Methimazole is combined with Vedolizumab. Velpatasvir The metabolism of Velpatasvir can be decreased when combined with Methimazole. Vemurafenib The metabolism of Vemurafenib can be decreased when combined with Methimazole. Venetoclax The metabolism of Venetoclax can be decreased when combined with Methimazole. Venlafaxine The metabolism of Venlafaxine can be decreased when combined with Methimazole. Verapamil The metabolism of Verapamil can be decreased when combined with Methimazole. Vernakalant The metabolism of Vernakalant can be decreased when combined with Methimazole. Vibrio cholerae The therapeutic efficacy of Vibrio cholerae CVD 103-HgR strain live antigen can be decreased when used in combination with Methimazole. Vilanterol The serum concentration of Vilanterol can be increased when it is combined with Methimazole. Vilazodone The metabolism of Vilazodone can be decreased when combined with Methimazole. Viloxazine Methimazole may decrease the excretion rate of Viloxazine which could result in a higher serum level. Vinblastine The metabolism of Vinblastine can be decreased when combined with Methimazole. Vincristine The metabolism of Vincristine can be decreased when combined with Methimazole. Vindesine The metabolism of Vindesine can be decreased when combined with Methimazole. Vinflunine The metabolism of Vinflunine can be decreased when combined with Methimazole. Vinorelbine The metabolism of Vinorelbine can be decreased when combined with Methimazole. Vitamin D The metabolism of Vitamin D can be decreased when combined with Methimazole. Vitamin E The metabolism of Vitamin E can be decreased when combined with Methimazole. Voclosporin The metabolism of Voclosporin can be decreased when combined with Methimazole. Vonoprazan The metabolism of Vonoprazan can be decreased when combined with Methimazole. Vorapaxar The metabolism of Vorapaxar can be decreased when combined with Methimazole. Voriconazole The metabolism of Voriconazole can be decreased when combined with Methimazole. Vorinostat The risk or severity of adverse effects can be increased when Methimazole is combined with Vorinostat. Vortioxetine The metabolism of Vortioxetine can be decreased when combined with Methimazole. Voxelotor The serum concentration of Voxelotor can be increased when it is combined with Methimazole. Voxilaprevir The metabolism of Voxilaprevir can be decreased when combined with Methimazole. Warfarin Methimazole may decrease the anticoagulant activities of Warfarin. Ximelagatran Methimazole may increase the anticoagulant activities of Ximelagatran. Yellow fever vaccine The risk or severity of infection can be increased when Yellow fever vaccine is combined with Methimazole. Yohimbine The metabolism of Yohimbine can be decreased when combined with Methimazole. Zafirlukast The metabolism of Zafirlukast can be decreased when combined with Methimazole. Zaleplon The metabolism of Zaleplon can be decreased when combined with Methimazole. Zanamivir Zanamivir may decrease the excretion rate of Methimazole which could result in a higher serum level. Zanubrutinib The metabolism of Zanubrutinib can be decreased when combined with Methimazole. Zidovudine The metabolism of Zidovudine can be decreased when combined with Methimazole. Zileuton The metabolism of Zileuton can be decreased when combined with Methimazole. Zimelidine The therapeutic efficacy of Methimazole can be decreased when used in combination with Zimelidine. Ziprasidone The metabolism of Ziprasidone can be decreased when combined with Methimazole. Zolmitriptan The metabolism of Zolmitriptan can be decreased when combined with Methimazole. Zolpidem The metabolism of Zolpidem can be decreased when combined with Methimazole. Zonisamide The metabolism of Zonisamide can be decreased when combined with Methimazole. Zopiclone The metabolism of Zopiclone can be decreased when combined with Methimazole. Zotepine The metabolism of Zotepine can be decreased when combined with Methimazole. Zuclopenthixol The metabolism of Zuclopenthixol can be decreased when combined with Methimazole. Pregnancy and Lactation Pregnancy and Lactation Use during Lactation Maternal methimazole therapy does not affect thyroid function or intellectual development in breastfed infants with doses up to 20 mg daily. Taking methimazole right after nursing and waiting for 3 to 4 hours before nursing again should minimize the infant dosage. No cases of thyroid function alteration have been reported among infants exposed to methimazole via breastmilk. Some experts now recommend that methimazole should be considered the antithyroid drug of choice in nursing mothers. The American Thyroid Association recommends only monitoring infants for appropriate growth and development during routine pediatric health and wellness evaluations and routine assessment of serum thyroid function in the child is not recommended. Rare idiosyncratic reactions (e.g., agranulocytosis) might occur, and the infant should be watched for signs of infection. Monitoring of the infant's complete blood count and differential is advisable if there is a suspicion of a drug-induced blood dyscrasia. Effects in Breastfed Infants Five mothers taking methimazole 5 to 15 mg daily at 6 pm breastfed their infants during the day using expressed milk or formula at night. Thyroid Five mothers taking methimazole 5 to 15 mg daily at 6 pm breastfed their infants during the day using expressed milk or formula at night. Thyroid function test remained normal during 90 days of study and none of the infants showed any clinical signs of hypothyroidism and methimazole was undetectable (<10 mcg/L) in the infants' serum. Twelve mothers taking methimazole 5 mg daily breastfed their infants from the time of delivery. Another 17 women were given methimazole 5 mg twice daily beginning 2 to 8 months postpartum and allowed to breastfeed their infants exclusively with supplementation given to those over 6 months of age. A third group of 6 mothers took methimazole 10 mg twice daily. All infants were normal clinically and had normal thyroid function tests when measured 2 to 4 weeks after the start of therapy. (Note: this paper is apparently the full publication of a previous report in abstract form.) The breastfed infants of 16 mothers who became hypothyroid during methimazole therapy were studied 5 times between birth and 12 months of age in comparison to a control group of 18 breastfed infants whose mothers did not become hypothyroid during methimazole therapy and a group of 24 infants of normal mothers. There were no differences in thyroid function tests of the infants from the 3 groups. Fifty-one infants of mothers who took methimazole during pregnancy and continued during lactation with a dose of 5 mg daily and 88 infants of mothers who took the drug starting 2 to 8 months postpartum were studied. All infants had normal thyroid function tests for up to a year of maternal therapy with doses of 5 to 20 mg daily of methimazole. Fourteen children who had been breastfed as infants were compared to a control group of children whose mothers did not take methimazole. Performance on IQ tests did not differ between the two groups. Forty-two of these children were restudied after 4 years of age and found to have IQ scores equal to children under the age of 6 in a matched control group. Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date. How should this medicine be used?

Methimazole comes as a tablet and usually is taken three times a day, approximately every 8 hours, with food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand.

What special precautions should I follow?

Before taking methimazole, tell your doctor and pharmacist if you are allergic to methimazol, lactose, or any other drugs. tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially anticoagulants ('blood thinners') such as warfarin (Coumadin), beta blockers such as propranolol (Inderal), diabetes medications, digoxin (Lanoxin), theophylline (Theobid, Theo-Dur), and vitamins. tell your doctor if you have or have ever had any blood disease, such as decreased white blood cells (leukopenia), decreased platelets (thrombocytopenia), or aplastic…

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to…

References

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