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Drug interactions

Efavirenz + Fedratinib

Severity: Major

Efavirenz and Fedratinib: 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

Efavirenz is expected to lower fedratinib concentrations and may reduce its efficacy in myelofibrosis. The combination has not been studied.

What this interaction means in plain words

Efavirenz and Fedratinib 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.

Efavirenz belongs to Anti Virals; Fedratinib belongs to Oncology.

Evidence level: Low

Why it happens

Efavirenz induces CYP3A4, a main metabolic pathway of fedratinib.

What to do

Avoid the combination and choose a non-inducing antiretroviral. If unavoidable, monitor spleen response and symptoms.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Efavirenz with Fedratinib?

MediHelp rates the interaction as major. Efavirenz and Fedratinib 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. Efavirenz is expected to lower fedratinib concentrations and may reduce its efficacy in myelofibrosis. The combination has not been studied.

How serious is the interaction between Efavirenz and Fedratinib?

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 and choose a non-inducing antiretroviral. If unavoidable, monitor spleen response and symptoms.

What other medicines interact with Efavirenz?

MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.

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