Diltiazem/Cardizem; Uses, Dosage, Side Effects, Interactions

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Diltiazem is a benzothiazepine derivative with anti-hypertensive, antiarrhythmic properties. Diltiazem blocks voltage-sensitive calcium channels in the blood vessels, by inhibiting the ion-control gating mechanisms, thereby preventing calcium levels increase by other revenues. Alternatively, it has been suggested that this agent also interferes with the release of calcium from the sarcoplasmic reticulum and inhibits the influx of...

For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

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Article Summary

Diltiazem is a benzothiazepine derivative with anti-hypertensive, antiarrhythmic properties. Diltiazem blocks voltage-sensitive calcium channels in the blood vessels, by inhibiting the ion-control gating mechanisms, thereby preventing calcium levels increase by other revenues. Alternatively, it has been suggested that this agent also interferes with the release of calcium from the sarcoplasmic reticulum and inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The overall low calcium levels lead to dilatation of the main coronary...

Key Takeaways

  • This article explains Mechanism of action of Diltiazem  in simple medical language.
  • This article explains Indications of Diltiazem  in simple medical language.
  • This article explains Contra-Indications of Diltiazem  in simple medical language.
  • This article explains Dosage of diltiazem  in simple medical language.
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Seek urgent medical care if you notice

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  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
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Definition

Diltiazem is a benzothiazepine derivative with anti-hypertensive, antiarrhythmic properties. Diltiazem blocks voltage-sensitive calcium channels in the blood vessels, by inhibiting the ion-control gating mechanisms, thereby preventing calcium levels increase by other revenues. Alternatively, it has been suggested that this agent also interferes with the release of calcium from the sarcoplasmic reticulum and inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The overall low calcium levels lead to dilatation of the main coronary and systemic arteries and decreasing myocardial contractility, decreased peripheral arterial resistance, improved oxygen delivery to the myocardial tissue, and decreased cardiac output.

Diltiazem (INN) is a nondihydropyridine (non-DHP) calcium channel blocker used in the treatment of hypertensionangina pectoris, and some types of arrhythmia. It relaxes the smooth muscles in the walls of arteries, which opens (dilates) the arteries, allows blood to flow more easily, and lowers blood pressure. Additionally, it lowers blood pressure by acting on the heart itself to reduce the rate, strength, and conduction speed of each beat. It is also used off-label as an effective preventive medication for a pain, nausea, or light sensitivity. সহজ বাংলা: বারবার হওয়া বিশেষ ধরনের মাথাব্যথা।" data-rx-term="migraine" data-rx-definition="Migraine is a recurring headache disorder often with throbbing pain, nausea, or light sensitivity. সহজ বাংলা: বারবার হওয়া বিশেষ ধরনের মাথাব্যথা।">migraine. It is a class 3 antianginal drug, and a class IV antiarrhythmic.

Mechanism of action of Diltiazem 

Possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, diltiazem, like verapamil, inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The resultant inhibition of the contractile processes of the myocardial smooth muscle cells leads to dilation of the coronary and systemic arteries and improved oxygen delivery to the myocardial tissue. Diltiazem is a non-dihydropyridine (DHP)member of the calcium channel blocker class, along with Verapamil. Diltiazem is similar to other peripheral vasodilators. Diltiazem inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum. The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload.

or

The effects of D-cis- and L-cis-diltiazem on the hydrogen peroxide (H2O2)-induced derangements of mechanical function and energy metal, and accumulation of intracellular Na+ was studied in isolated rat hearts. The intracellular content of Na+ ([Na+]i) in the myocardium was measured using a nuclear magnetic resonance technique. H2O2 (600 uM) increased the left ventricular end-diastolic pressure, decreased the tissue level of ATP, and increased the release of lactate dehydrogenase from the myocardium. These alterations induced by H2O2 were significantly attenuated by D-cis-diltiazem(15 uM) or L-cis-diltiazem (15 uM). H2O2 (1 mM) produced a marked incr in the myocardial [Na+]i, which was effectively inhibited by … D-cis-diltiazem (15 uM) or L-cis-diltiazem (15 uM). The protective action of D-cis- and L-cis-diltiazem may be due to their ability to inhibit the H2O2-induced incr in [Na+] I, at least in part.

Indications of Diltiazem 

  • Angina Pectoris Prophylaxis
  • Heart Failure
  • Anginal Pain
  • Atrial Flutter
  • High Blood Pressure (Hypertension)
  • Nonvalvular Atrial Fibrillation
  • Paroxysmal Supraventricular Tachycardia
  • Chronic, stable Angina pectoris
  • Anal Fissures

Contra-Indications of Diltiazem 

  • Complete Heart Block
  • Second Degree Atrioventricular Heart Block
  • Wolff-Parkinson-White Syndrome
  • Sick Sinus Syndrome
  • Slow Heartbeat
  • suddenly serious symptoms of heart failure
  • abnormally low blood pressure
  • Severely Low Blood Pressure
  • liver problems
  • kidney disease with a reduction in kidney function
  • chronic idiopathic constipation
  • Lown-Ganong-Levine Syndrome
  • Allergies to Calcium Channel Blockers
  • Calcium Channel Blocking Agent diltiazem Analogues

Dosage of diltiazem 

Strengths: 30 mg; 60 mg; 90 mg; 120 mg; 5 mg/mL; 120 mg/24 hours; 180 mg/24 hours

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For chest pain

For oral dosage form (extended-release capsules)

  • Adults—At first, 120 milligrams (mg) once a day in the morning. Your doctor may adjust your dose if needed.
  • Children—Use and dose must be determined by your doctor.

For oral dosage form (extended-release tablets)

  • Adults—At first, 180 milligrams (mg) once a day, either in the morning or evening. Your doctor may adjust your dose if needed.
  • Children—Use and dose must be determined by your doctor.

For oral dosage form (tablets)

  • Adults—At first, 30 milligrams (mg) four times a day before meals and at bedtime. Your doctor may increase your dose if needed.
  • Children—Use and dose must be determined by your doctor.

For high blood pressure

For oral dosage form (extended-release capsules)

  • Adults—At first, 180 to 240 milligrams (mg) once a day in the morning. Your doctor may adjust your dose if needed.
  • Children—Use and dose must be determined by your doctor.

For oral dosage form (extended-release tablets)

  • Adults—At first, 180 to 240 milligrams (mg) once a day, either in the morning or at bedtime. Your doctor may adjust your dose if needed.
  • Children—Use and dose must be determined by your doctor.

Side Effects of Diltiazem 

The most common

 Common

Rare

  • Body aches or pain
  • congestion
  • cough
  • dryness or soreness of the throat
  • fever
  • hoarseness
  • a runny nose
  • tender or swollen glands in the neck
  • trouble swallowing
  • voice changes

Drug Interactions of Diltiazem 

Cardizem or diltiazem may interact with following drugs, supplements & may change the efficacy of the drug

Pregnancy & Lactation of Diltiazem

FDA Pregnancy Category C 

Pregnancy

Women who are or may become pregnant should not take diltiazem. If you become pregnant while taking this medication, contact your doctor immediately.

Lactation

Diltiazem passes into breast milk. If you are a breastfeeding mother and are taking diltiazem, it may affect your baby. Talk to your doctor about whether you should continue breastfeeding.

References

 

Diltiazem/Cardizem; Uses, Dosage, Side Effects, Interactions

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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.

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

Safe first steps

  • Drink safe fluids and monitor temperature.
  • In dengue-prone areas, discuss CBC and platelet count when fever persists or warning signs appear.
  • Use tepid sponging for high fever discomfort; avoid ice-cold bathing.

OTC medicine safety

  • For fever, common fever medicine may be discussed with a clinician or pharmacist.
  • Avoid aspirin/ibuprofen-like medicines in suspected dengue unless a doctor says it is safe.

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

  • Fever with breathing difficulty, confusion, repeated vomiting, bleeding, severe weakness, stiff neck, or dehydration 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

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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: Diltiazem/Cardizem; Uses, Dosage, Side Effects, Interactions

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.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

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Frequently Asked Questions

Is this article a replacement for a doctor?

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When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

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