Drug interactions
Ivacaftor + Lapatinib
Severity: Moderate
Ivacaftor and Lapatinib: 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
Lapatinib may raise ivacaftor levels through CYP3A4 inhibition, and ivacaftor can inhibit P-gp, potentially raising lapatinib exposure. Increased exposure could cause more adverse effects from either drug.
What this interaction means in plain words
Ivacaftor and Lapatinib 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.
Ivacaftor belongs to Miscellaneous; Lapatinib belongs to Oncology.
Why it happens
Lapatinib inhibits CYP3A4 metabolism of ivacaftor, while ivacaftor inhibits P-gp efflux of lapatinib.
What to do
Monitor for adverse effects of both drugs, including liver tests, and reduce the ivacaftor dose per product labeling if a moderate CYP3A4 inhibitor is used.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Ivacaftor and Lapatinib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Ivacaftor
- Ensitrelvir + Ivacaftor Contraindicated
- Apalutamide + Ivacaftor Major
- Carbamazepine + Ivacaftor Major
- Clarithromycin + Ivacaftor Major
- Efavirenz + Ivacaftor Major
- Enzalutamide + Ivacaftor Major
Frequently asked questions
Can I take Ivacaftor with Lapatinib?
MediHelp rates the interaction as moderate. Ivacaftor and Lapatinib 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 may raise ivacaftor levels through CYP3A4 inhibition, and ivacaftor can inhibit P-gp, potentially raising lapatinib exposure. Increased exposure could cause more adverse effects from either drug.
How serious is the interaction between Ivacaftor and Lapatinib?
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 adverse effects of both drugs, including liver tests, and reduce the ivacaftor dose per product labeling if a moderate CYP3A4 inhibitor is used.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
