Drug interactions
Lapatinib + Neratinib
Severity: Major
Lapatinib and Neratinib: 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
Neratinib is a CYP3A4 and P-gp substrate and lapatinib may increase its exposure. Higher neratinib levels can worsen diarrhea and hepatotoxicity. Both are HER2 tyrosine kinase inhibitors, so the combination offers little therapeutic rationale.
What this interaction means in plain words
Lapatinib and Neratinib 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; Neratinib belongs to Oncology.
Why it happens
CYP3A4 and P-gp inhibition by lapatinib reduces neratinib clearance.
What to do
Avoid concurrent use of these two HER2 inhibitors. If unavoidable, monitor for severe diarrhea and liver toxicity.
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 Neratinib
- Amiodarone + Neratinib Major
- Amobarbital + Neratinib Major
- Aprepitant + Neratinib Major
- Armodafinil + Neratinib Major
- Bosentan + Neratinib Major
- Carbamazepine + Neratinib Major
Frequently asked questions
Can I take Lapatinib with Neratinib?
MediHelp rates the interaction as major. Lapatinib and Neratinib 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. Neratinib is a CYP3A4 and P-gp substrate and lapatinib may increase its exposure. Higher neratinib levels can worsen diarrhea and hepatotoxicity. Both are HER2 tyrosine kinase inhibitors, so the combination offers little therapeutic rationale.
How serious is the interaction between Lapatinib and Neratinib?
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 concurrent use of these two HER2 inhibitors. If unavoidable, monitor for severe diarrhea and liver toxicity.
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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