Drug interactions
Lapatinib + Quinupristin / dalfopristin
Severity: Moderate
Lapatinib and Quinupristin / dalfopristin: 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
Quinupristin/dalfopristin inhibits CYP3A4 and may raise lapatinib concentrations, increasing the risk of diarrhea, hepatotoxicity and QT prolongation.
What this interaction means in plain words
Lapatinib and Quinupristin / dalfopristin 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.
Why it happens
Inhibition of CYP3A4 by quinupristin/dalfopristin reduces lapatinib metabolism.
What to do
Monitor ECG and for lapatinib toxicity during the short antibiotic course, and consider reducing the lapatinib dose or choosing an alternative antibiotic.
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
Frequently asked questions
Can I take Lapatinib with Quinupristin / dalfopristin?
MediHelp rates the interaction as moderate. Lapatinib and Quinupristin / dalfopristin 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. Quinupristin/dalfopristin inhibits CYP3A4 and may raise lapatinib concentrations, increasing the risk of diarrhea, hepatotoxicity and QT prolongation.
How serious is the interaction between Lapatinib and Quinupristin / dalfopristin?
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 ECG and for lapatinib toxicity during the short antibiotic course, and consider reducing the lapatinib dose or choosing an alternative antibiotic.
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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