Drug interactions
Erlotinib + Lapatinib
Severity: Moderate
Erlotinib and Lapatinib: moderate 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
Lapatinib inhibits CYP3A4 and may increase erlotinib exposure, and both are EGFR-family tyrosine kinase inhibitors with overlapping toxicities. Rash, diarrhea and hepatotoxicity may be more frequent or severe.
What this interaction means in plain words
Erlotinib and Lapatinib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Erlotinib belongs to Oncology; Lapatinib belongs to Oncology.
Why it happens
Lapatinib inhibits CYP3A4 metabolism of erlotinib, plus overlapping pharmacodynamic toxicity.
What to do
Monitor for diarrhea, rash and liver function abnormalities. Reduce the erlotinib dose if toxicity develops.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Erlotinib
- Amobarbital + Erlotinib Major
- Apalutamide + Erlotinib Major
- Carbamazepine + Erlotinib Major
- Cobicistat + Erlotinib Major
- Darunavir + Erlotinib Major
- Dexlansoprazole + Erlotinib Major
Other interactions of Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Frequently asked questions
Can I take Erlotinib with Lapatinib?
MediHelp rates the interaction as moderate. Erlotinib and Lapatinib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Lapatinib inhibits CYP3A4 and may increase erlotinib exposure, and both are EGFR-family tyrosine kinase inhibitors with overlapping toxicities. Rash, diarrhea and hepatotoxicity may be more frequent or severe.
How serious is the interaction between Erlotinib and Lapatinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for diarrhea, rash and liver function abnormalities. Reduce the erlotinib dose if toxicity develops.
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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