Drug interactions
Fedratinib + Isoniazid
Severity: Major
Fedratinib and Isoniazid: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Isoniazid inhibits both CYP3A4 and CYP2C19, both of which metabolize fedratinib, so fedratinib exposure may rise. This could increase the risk of gastrointestinal toxicity, anemia, hepatotoxicity and encephalopathy, including Wernicke's.
What this interaction means in plain words
Fedratinib and Isoniazid can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Fedratinib belongs to Oncology; Isoniazid belongs to Anti Bacterial.
Why it happens
Isoniazid inhibits CYP3A4 and CYP2C19, the pathways that metabolize fedratinib.
What to do
Avoid the combination where possible, or monitor liver tests, blood counts and neurological status and consider reducing the fedratinib dose. Ensure thiamine status is assessed.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Isoniazid
Other interactions of Fedratinib
- Fedratinib + Thioridazine Contraindicated
- Amobarbital + Fedratinib Major
- Apalutamide + Fedratinib Major
- Brexpiprazole + Fedratinib Major
- Carbamazepine + Fedratinib Major
- Chloramphenicol + Fedratinib Major
Frequently asked questions
Can I take Fedratinib with Isoniazid?
MediHelp rates the interaction as major. Fedratinib and Isoniazid can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Isoniazid inhibits both CYP3A4 and CYP2C19, both of which metabolize fedratinib, so fedratinib exposure may rise. This could increase the risk of gastrointestinal toxicity, anemia, hepatotoxicity and encephalopathy, including Wernicke's.
How serious is the interaction between Fedratinib and Isoniazid?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible, or monitor liver tests, blood counts and neurological status and consider reducing the fedratinib dose. Ensure thiamine status is assessed.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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