Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Lapatinib
Severity: Major
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Lapatinib: 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
Cobicistat is a potent CYP3A4 inhibitor and is expected to considerably increase lapatinib exposure. This raises the risk of hepatotoxicity, diarrhea and QT prolongation.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Lapatinib 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.
Why it happens
Cobicistat inhibits CYP3A4 metabolism of lapatinib.
What to do
Avoid if possible by using another antiretroviral regimen. If co-administered, reduce the lapatinib dose and monitor ECG and liver function.
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
Frequently asked questions
Can I take Elvitegravir / cobicistat / emtricitabine / tenofovir df with Lapatinib?
MediHelp rates the interaction as major. Elvitegravir / cobicistat / emtricitabine / tenofovir df and Lapatinib 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. Cobicistat is a potent CYP3A4 inhibitor and is expected to considerably increase lapatinib exposure. This raises the risk of hepatotoxicity, diarrhea and QT prolongation.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df and Lapatinib?
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 by using another antiretroviral regimen. If co-administered, reduce the lapatinib dose and monitor ECG and liver function.
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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