Drug interactions
Irinotecan + Verapamil
Severity: Moderate
Irinotecan and Verapamil: 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
Verapamil may increase exposure to irinotecan and its active metabolite SN-38 through CYP3A4 and transporter effects. This could worsen diarrhea and neutropenia. However, CYP3A4 also forms inactive metabolites, so the net effect is uncertain.
What this interaction means in plain words
Irinotecan and Verapamil 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.
Irinotecan belongs to Oncology; Verapamil belongs to Cardiovascular.
Why it happens
Possible inhibition of CYP3A4 and P-gp, altering irinotecan disposition; the net effect on SN-38 exposure is not firmly established.
What to do
Monitor for severe diarrhea and neutropenia with blood counts during irinotecan cycles. Consider an alternative antihypertensive or antiarrhythmic if toxicity develops.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Other interactions of Irinotecan
- Clozapine + Irinotecan Contraindicated
- Irinotecan + Sacituzumab govitecan Contraindicated
- Adenovirus types 4 and 7 live + Irinotecan Major
- Apalutamide + Irinotecan Major
- Atazanavir + Irinotecan Major
- Carbamazepine + Irinotecan Major
Frequently asked questions
Can I take Irinotecan with Verapamil?
MediHelp rates the interaction as moderate. Irinotecan and Verapamil 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. Verapamil may increase exposure to irinotecan and its active metabolite SN-38 through CYP3A4 and transporter effects. This could worsen diarrhea and neutropenia. However, CYP3A4 also forms inactive metabolites, so the net effect is uncertain.
How serious is the interaction between Irinotecan and Verapamil?
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 severe diarrhea and neutropenia with blood counts during irinotecan cycles. Consider an alternative antihypertensive or antiarrhythmic if toxicity develops.
What other medicines interact with Verapamil?
MediHelp also lists interactions of Verapamil with, for example, Dofetilide, Flibanserin, Lomitapide. The full list is on the Verapamil page.
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