Drug interactions
Lapatinib + Olaparib
Severity: Moderate
Lapatinib and Olaparib: 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
Olaparib is a CYP3A4 substrate and lapatinib may moderately increase its exposure. This may increase anemia, nausea and other olaparib toxicities.
What this interaction means in plain words
Lapatinib and Olaparib 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 belongs to Oncology; Olaparib belongs to Oncology.
Why it happens
CYP3A4 inhibition by lapatinib reduces olaparib clearance.
What to do
Monitor blood counts and tolerability. If coadministration is needed, reduce the olaparib dose as recommended for moderate CYP3A inhibitors.
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 Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Other interactions of Olaparib
- Amiodarone + Olaparib Major
- Amobarbital + Olaparib Major
- Apalutamide + Olaparib Major
- Aprepitant + Olaparib Major
- Azathioprine + Olaparib Major
- Carbamazepine + Olaparib Major
Frequently asked questions
Can I take Lapatinib with Olaparib?
MediHelp rates the interaction as moderate. Lapatinib and Olaparib 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. Olaparib is a CYP3A4 substrate and lapatinib may moderately increase its exposure. This may increase anemia, nausea and other olaparib toxicities.
How serious is the interaction between Lapatinib and Olaparib?
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 blood counts and tolerability. If coadministration is needed, reduce the olaparib dose as recommended for moderate CYP3A inhibitors.
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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