Drug interactions
Lapatinib + Rifapentine
Severity: Major
Lapatinib and Rifapentine: 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
Rifapentine is a strong CYP3A4 inducer and can substantially reduce lapatinib exposure, risking treatment failure.
What this interaction means in plain words
Lapatinib 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.
Lapatinib belongs to Oncology; Rifapentine belongs to Anti Bacterial.
Why it happens
Induction of CYP3A4 by rifapentine increases lapatinib clearance.
What to do
Avoid combination and choose alternative therapy. If unavoidable, labeling for strong inducers advises gradual lapatinib dose escalation with close monitoring, then dose reduction 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?
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Other interactions of Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Other interactions of Rifapentine
- Ledipasvir-sofosbuvir + Rifapentine Contraindicated
- Lorlatinib + Rifapentine Contraindicated
- Lurasidone + Rifapentine Contraindicated
- Ranolazine + Rifapentine Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Lapatinib with Rifapentine?
MediHelp rates the interaction as major. Lapatinib 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 is a strong CYP3A4 inducer and can substantially reduce lapatinib exposure, risking treatment failure.
How serious is the interaction between Lapatinib 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 combination and choose alternative therapy. If unavoidable, labeling for strong inducers advises gradual lapatinib dose escalation with close monitoring, then dose reduction after rifapentine is stopped.
What other medicines interact with Lapatinib?
MediHelp also lists interactions of Lapatinib with, for example, Dofetilide, Ibutilide, Pimozide. The full list is on the Lapatinib page.
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