Drug interactions
Lapatinib + Lopinavir
Severity: Major
Lapatinib and Lopinavir: 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
Lopinavir/ritonavir strongly inhibits CYP3A4 and can substantially increase lapatinib exposure. This increases the risk of QT prolongation, hepatotoxicity and diarrhea. Both drugs can also prolong the QT interval.
What this interaction means in plain words
Lapatinib and Lopinavir 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; Lopinavir belongs to Anti Virals.
Why it happens
CYP3A4 inhibition (mainly via the ritonavir component) reduces lapatinib metabolism, with additive QT effects.
What to do
Avoid if possible and choose an alternative antiretroviral. If necessary, reduce the lapatinib dose per labeling and monitor ECG and liver tests.
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 Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Lapatinib with Lopinavir?
MediHelp rates the interaction as major. Lapatinib and Lopinavir 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. Lopinavir/ritonavir strongly inhibits CYP3A4 and can substantially increase lapatinib exposure. This increases the risk of QT prolongation, hepatotoxicity and diarrhea. Both drugs can also prolong the QT interval.
How serious is the interaction between Lapatinib and Lopinavir?
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 if possible and choose an alternative antiretroviral. If necessary, reduce the lapatinib dose per labeling and monitor ECG and liver tests.
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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