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Drug interactions

Erlotinib + Rifapentine

Severity: Major

Erlotinib and Rifapentine: major interaction.

Last updated Sources: US FDA label

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

Rifapentine induces CYP3A4 and can substantially reduce erlotinib exposure. This may lead to loss of efficacy.

What this interaction means in plain words

Erlotinib and Rifapentine 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.

Erlotinib belongs to Oncology; Rifapentine belongs to Anti Bacterial.

Evidence level: High

Why it happens

Rifapentine induces CYP3A4 (and other enzymes), increasing erlotinib clearance.

What to do

Avoid the combination when an alternative exists. If required, consider increasing the erlotinib dose with monitoring of tolerability and response, and reduce it after rifapentine is stopped.

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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References

Frequently asked questions

Can I take Erlotinib with Rifapentine?

MediHelp rates the interaction as major. Erlotinib and Rifapentine 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. Rifapentine induces CYP3A4 and can substantially reduce erlotinib exposure. This may lead to loss of efficacy.

How serious is the interaction between Erlotinib and Rifapentine?

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 when an alternative exists. If required, consider increasing the erlotinib dose with monitoring of tolerability and response, and reduce it after rifapentine is stopped.

What other medicines interact with Erlotinib?

MediHelp also lists interactions of Erlotinib with, for example, Amobarbital, Apalutamide, Carbamazepine. The full list is on the Erlotinib page.

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