Fedratinib – Uses, Dosage, Side Effects, Interaction

Fedratinib - Uses, Dosage, Side Effects, Interaction
Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

On this page12 sections

Article Summary

Fedratinib is an orally bioavailable, small-molecule, ATP-competitive inhibitor of Janus-associated kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3; CD135; STK1; FLK2), with potential antineoplastic activity. Upon oral administration, fedratinib competes with wild-type JAK2 as well as mutated forms for ATP binding, which may result in inhibition of JAK2 activation, inhibition of the JAK-STAT signaling pathway, inhibition of tumor cell proliferation and induction of tumor cell apoptosis. JAK2 is 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 Dosage in simple medical language.
Before reading

RX Patient Tools

Use these quick guides before reading the article, or return to them when you need help preparing questions for a doctor.

Start here Choose the right pathway for symptoms, reports, medicines, or urgent warning signs. Disease article roadmap Read this topic step by step: meaning, symptoms, warning signs, diagnosis, treatment, prevention, and follow-up. Treatment planner Prepare questions about treatment choices, benefits, risks, side effects, and follow-up. Family & caregiver guide Organize symptoms, reports, medicines, questions, and follow-up safely. Nutrition & diet guide Prepare food, hydration, supplement, and medicine-timing questions safely. Prevention guide Organize risk factors, protective habits, screening, and warning signs. Recovery guide Prepare a safe plan for activity, rehabilitation, warning signs, and follow-up.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.
Choose your reading view

Patient View highlights a simple learning journey. Clinical View reveals structure, evidence, and editorial completeness.

Mechanism of Action

Fedratinib is an inhibitor of Janus Activated Kinase 2 (JAK2) and FMS-like tyrosine kinase 3. JAK2 is highly active in myeloproliferative neoplasms like myelofibrosis. Fedratinib’s inhibition of JAK2 inhibits phosphorylation of signal transducer and activator of transcription (STAT) 3 and 5, which prevents cell division and induces apoptosis.

Fedratinib is a kinase inhibitor that inhibits cell division and induces apoptosis. Patients taking fedratinib may experience , , gastrointestinal toxicity, hepatic toxicity, or elevated amylase and lipase. These effects should be managed by reducing the dose, temporarily stopping the medication, or providing transfusions on a case-by-case basis.

Fedratinib acts as a competitive inhibitor of protein kinase JAK-2 with IC50=6 nM; related kinases FLT3 and RET are also sensitive, with IC50=25 nM and IC50=17 nM, respectively. Significantly less activity was observed against other tyrosine kinases including JAK3 (IC50=169 nM). In treated cells, the inhibitor blocks downstream cellular signaling (JAK-STAT) leading to the suppression of proliferation and induction of apoptosis.

Indications

  • Fedratinib is indicated to treat adults with primary or secondary myelofibrosis that is either intermediate-2 or high-risk.
  • Arabic is indicated for the treatment of disease-related splenomegaly or symptoms in adult patients with primary myelofibrosis, post vera myelofibrosis, or post essential thrombocythaemia myelofibrosis who are Janus Associated Kinase (JAK) inhibitor naïve or have been treated with ruxolitinib.
  • Fedratinib is an oral selective inhibitor of Janus-associated kinase 2 (JAK-2) and FMS-like tyrosine kinase 3 (FLT3) that is used in the therapy of intermediate or high-risk, primary or secondary myelofibrosis
  • Fedratinib hydrochloride is approved for use in adults to treat: Myelofibrosis (a disease) that is an intermediate-2 risk or high risk, including the following types: Primary myelofibrosis. Post-polycythemia vera myelofibrosis. Post-essential thrombocythemia myelofibrosis.
  • Fedratinib hydrochloride is also being studied in the treatment of other conditions.
  • For the treatment of intermediate-2 or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF)
  • In the United States, fedratinib is indicated for the treatment of adults with intermediate-2 or high-risk primary or secondary (following polycythemia vera or essential thrombocythemia) myelofibrosis.
  • Primary Myelofibrosis (PMF)
  • Secondary Myelofibrosis

Use in Cancer

Toremifene is approved to treat:

Contraindications

  • A High Alanine Transaminase Level
  • A High Aspartate Transaminase Level
  • Low Amount Of Sodium In The Blood
  • Decreased Blood Platelets
  • A Type Of Brain Function Problem Called Encephalopathy
  • High Blood Pressure
  • A Low Supply Of Oxygen Rich Blood To The Heart
  • High Blood Levels Of The Lipase Enzyme
  • High Blood Levels Of The Amylase Enzyme
  • Difficult Or Painful Urination
  • Wernicke’s Encephalopathy

Strengths: 100 mg

Myelofibrosis

For patients with a count of 50 x 109/L or greater:

  • 400 mg orally once a day

Management of thiamine levels and Wernicke’s encephalopathy (WE):

  • Assess thiamine levels and nutritional status prior to starting therapy, periodically during therapy, and as indicated.
  • Do not initiate this drug in patients with thiamine deficiency; replete thiamine prior to therapy initiation and during therapy if thiamine levels are low.
  • If Wernicke’s encephalopathy is suspected, immediately discontinue therapy and initiate parenteral thiamine treatment.
  • Monitor until symptoms resolve or improve and thiamine levels normalize.

Dose Adjustments

  • Discontinue therapy in patients unable to tolerate 200 mg daily. Consider dose reductions in patients who become transfusion-dependent during therapy with this drug.

DOSE MODIFICATIONS WITH CONCOMITANT USE OF STRONG CYP450 3A4 INHIBITORS:

  • Reduce the dose of this drug when administering with strong CYP450 3A4 inhibitors to 200 mg orally once a day.
  • If the strong CYP450 3A4 inhibitor is discontinued, increase the dose of this drug to 300 mg orally once d day during the first 2 weeks after discontinuation of the CYP450 3A4 inhibitor, and then to 400 mg orally once a day thereafter as tolerated.

DOSE MODIFICATIONS FOR HEMATOLOGIC ADVERSE REACTIONS:

  • Grade 4 thrombocytopenia or Grade 3 thrombocytopenia with active bleeding: Withhold therapy until resolved to Grade 2 or less or baseline; restart at 100 mg daily below the last given dose.
  • Grade 4 : Withhold therapy until resolved to Grade 2 or less or baseline, restart dose at 100 mg daily below the last given dose.

`DOSE MODIFICATIONS FOR NONHEMATOLOGIC ADVERSE REACTIONS:

  • Grade 3 or higher , , or not responding to supportive measures within 48 hours: Withhold therapy until resolved to Grade 1 or less or baseline; restart dose at 100 mg daily below the last given dose.
  • Grade 3 or higher ALT, AST, or : Withhold therapy until resolved to Grade 1 or less or baseline; restart dose at 100 mg daily below the last given dose; monitor ALT, AST, and bilirubin (total and direct) more frequently following the dose reduction; if reoccurrence of Grade 3 or higher elevation, discontinue therapy.
  • Grade 3 or higher other nonhematologic toxicities: Withhold therapy until resolved to Grade 1 or less or baseline; restart dose at 100 mg daily below the last given dose.

Administration advice:

  • This drug may be taken with or without food.
  • Administration of a high-fat meal may reduce the incidence of nausea and vomiting.
  • If a dose is missed, the next scheduled dose should be taken the following day.
  • Patients taking ruxolitinib before initiation of this drug should taper and discontinue according to the ruxolitinib prescribing information.

Side Effects

The Most Common

  • nausea
  • vomiting
  • diarrhea
  • tiredness
  • muscle spasms
  • arm, leg, or
  • weight gain
  • unusual bleeding or
  • , , , painful or , or other signs of
  • nausea, extreme tiredness, unusual bruising or bleeding, lack of energy, , in the upper right part of the stomach, yellowing of the skin or eyes, or flu-like symptoms
  • shortness of breath, fast heartbeat, headache, dizziness, pale skin, confusion, or tiredness
  • pain in the chest, arms, back, neck, jaw, or stomach; breaking out in cold sweat; lightheadedness
  • slow or difficult speech; sudden weakness or numbness of the face, arm or leg; sudden headache; sudden vision problems; sudden difficulty walking
  • swelling, pain, tenderness, warmth or redness in one or both legs
  • shortness of breath, coughing up blood, fast heartbeat, fast breathing, pain when breathing deeply

More common

  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • chills
  • cough
  • fever
  • lower back or side pain
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • sore throat
  • troubled breathing with exertion
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • Bone pain
  • diarrhea
  • dizziness
  • headache
  • lack or loss of strength
  • muscle spasms
  • nausea
  • pain in the arms or legs
  • vomiting
  • weight gain

Rare

  • Bladder pain
  • cloudy urine
  • confusion
  • difficult, burning, or painful urination
  • drowsiness
  • frequent urge to urinate
  • lower back or side pain
  • shakiness and unsteady walk
  • trouble remembering
  • uncontrolled eye movements
  • unsteadiness, trembling, or other problems with muscle control or coordination

Drug Interactions

Pregnancy and Lactation

US FDA pregnancy category: Not assigned.

Pregnancy

This drug should be used during pregnancy only if the benefit outweighs the risk. Adequate methods of contraception should be encouraged. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.

Lactation

  • A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.
  • Excreted into human milk: Unknown
  • Excreted into animal milk: Data not available
  • Because of the potential for serious adverse reactions in a breastfed child, advise patients not to breastfeed during therapy and for at least 1 month after.

How should this medicine be used?

Fedratinib comes as a capsule to take by mouth. It is usually taken once a day, with or without food. Taking fedratinib with a high fat meal may help to reduce nausea and vomiting. Take fedratinib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take fedratinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will order blood tests before and during your treatment to see how you are affected by this medication. Your doctor may increase or decrease your dose of fedratinib during your treatment, or may tell you to stop taking fedratinib temporarily or permanently. This depends on how well the medication works for you, your lab test results, and if you experience side effects. Talk to your doctor about how you are feeling during your treatment.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking fedratinib,

  • tell your doctor and pharmacist if you are allergic to fedratinib, any other medications, or any of the ingredients in fedratinib capsules. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: clarithromycin (Biaxin, in PrevPac), diltiazem (Cardizem, Dilacor, Tiazac, others), erythromycin (E.E.S., E-mycin, Erythrocin), idelalisib (Zydelig), indinavir (Crixivan), itraconazole (Sporanox), ketoconazole (Nizoral), metoprolol (Lopressor, Toprol XL, in Dutoprol, others), midazolam (Versed), nefazodone, nelfinavir (Viracept), omeprazole (Prilosec, in Zegerid), pantoprazole (Protonix), ribociclib (Kisqali, Kisqali, in Femera), ritonavir (Norvir), ruxolitinib (Jakafi), and saquinavir (Invirase). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with fedratinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor if you if you smoke or if you have ever smoked. Also tell your doctor if you have or have ever had cancer, pancreatitis (swelling of the pancreas), blood clots, a stroke, a heart attack or other heart problems, liver or kidney disease.
  • tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking fedratinib, call your doctor.
  • do not breastfeed during your treatment with fedratinib and for at least 1 month after your final dose.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking fedratinib.

References

  1. https://www.cancer.gov/about-cancer/treatment/drugs/fedratinibhydrochloride
  2. https://www.drugs.com/mtm/fedratinib.html
  3. https://medlineplus.gov/druginfo/meds/a619058.html
  4. https://go.drugbank.com/drugs/DB12500
  5. https://en.wikipedia.org/wiki/Fedratinib
  6. https://www.mayoclinic.org/drugs-supplements/fedratinib-oral-route/side-effects/drg-20469997https://www.mayoclinic.org/drugs-supplements/fedratinib-oral-route/side-effects/drg-20469997
  7. https://pubchem.ncbi.nlm.nih.gov/compound/Fedratinib
  8. https://pubchem.ncbi.nlm.nih.gov/compound/Fedratinib-dihydrochloride-monohydrate
  9. https://www.webmd.com/drugs/2/drug-177751/fedratinib-oral/details/list-sideeffects
  10. ChemIDplus Chemical Information Classification
  11. CompTox Chemicals Dashboard Chemical Lists
  12. NCI Thesaurus Tree
  13. Guide to Pharmacology Target Classification
  14. PubChem
  15. Anatomical Therapeutic Chemical (ATC) classification
    Target-based classification of drugs
  16. NORMAN Suspect List Exchange Classification

RX Medical Knowledge Graph

Explore this medical topic

Continue through verified related conditions, investigations, medicines, and patient guides. These links are educational and do not replace professional medical advice.

RX Clinical Pathway Engine

Continue through a complete learning pathway

Move from understanding the topic to symptoms, tests, treatment, medicines, monitoring, and prevention.

Search the complete library
  1. Understand the condition Begin with the essential facts and a clear explanation of the topic.
  2. Recognize symptoms Learn common symptoms, signs, and patterns of presentation.
  3. Know when to seek help Review urgent warning signs and when professional assessment may be needed.
  4. Understand causes and risks Explore causes, risk factors, mechanisms, and contributing conditions.
  5. Explore tests and diagnosis Learn how clinicians assess the condition and which investigations may be discussed.
  6. Learn treatment approaches Review general treatment categories and management principles.
  7. Understand medicines safely Continue to medicine education, uses, precautions, and monitoring.
  8. Plan monitoring and follow-up Understand monitoring, complications, rehabilitation, and follow-up learning.
  9. Review prevention and self-care Explore prevention, healthy routines, and questions to discuss with a clinician.

Conditions & Diseases

Background, symptoms, causes, diagnosis, and care.

Explore this library

Tests & Investigations

Laboratory, imaging, screening, and diagnostic education.

Explore this library

Medicines

Uses, safety, monitoring, and related medicine knowledge.

Explore this library

Cancer Knowledge

Cancer types, screening, oncology, and treatment education.

Explore this library
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: Fedratinib – Uses, Dosage, Side Effects, Interaction

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.

Internal learning pathway

Explore related RX articles

Related guides from RX Harun are grouped to help readers move from overview to symptoms, tests, treatment, and safe next steps.

Drugs (A - Z)
  1. Vasodilator Drugs Vasodilator drugs relax and widen blood vessels, increasing blood flow. A few examples include ACE inhibitors, ARBs, calcium…
  2. Methamphetamine Hydrochloride – Uses, Dosage, Side Effects, Interaction Methamphetamine Hydrochloride is the hydrochloride salt form of methamphetamine, an amphetamine and sympathomimetic amine with CNS stimulating properties. Methamphetamine…
  3. Methamphetamine – Uses, Dosage, Side Effects, Interactions Methamphetamine is a member of the class of amphetamines in which the amino group of (S)-amphetamine carries a methyl substituent.…
  4. Vitamin D3 – Uses, Dosage, Side Effects, Interactions DefinitionCholecalciferol is a steroid? hormone produced in the skin when exposed to ultraviolet light or obtained from…
  5. Imidazole – Uses, Dosage, Side Effects, Interactions DefinitionImidazole is an imidazole tautomer which has the migrating hydrogen at position 1. It is a conjugate base of…
  6. Carbimazole Carbimazole is a member of the class of imidazoles that is methimazole in which the nitrogen-bearing hydrogen is…