Drug interactions
Lapatinib + Rucaparib
Severity: Moderate
Lapatinib and Rucaparib: 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
Rucaparib is a reversible inhibitor of CYP3A4 and may increase lapatinib concentrations. Higher lapatinib exposure could worsen diarrhea, hepatotoxicity and QT prolongation.
What this interaction means in plain words
Lapatinib and Rucaparib 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; Rucaparib belongs to Oncology.
Why it happens
Rucaparib inhibits CYP3A4, reducing the metabolism of lapatinib, a CYP3A4 substrate.
What to do
Monitor for lapatinib adverse effects including diarrhea, liver enzymes and QTc. Reduce the lapatinib dose if toxicity appears.
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 Rucaparib
- Cisapride + Rucaparib Major
- Ergotamine + Rucaparib Major
- Pimozide + Rucaparib Major
- Alfuzosin + Rucaparib Moderate
- Aripiprazole + Rucaparib Moderate
- Atorvastatin + Rucaparib Moderate
Frequently asked questions
Can I take Lapatinib with Rucaparib?
MediHelp rates the interaction as moderate. Lapatinib and Rucaparib 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. Rucaparib is a reversible inhibitor of CYP3A4 and may increase lapatinib concentrations. Higher lapatinib exposure could worsen diarrhea, hepatotoxicity and QT prolongation.
How serious is the interaction between Lapatinib and Rucaparib?
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 lapatinib adverse effects including diarrhea, liver enzymes and QTc. Reduce the lapatinib dose if toxicity appears.
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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