Drug interactions
Irinotecan + Tucatinib
Severity: Major
Irinotecan and Tucatinib: 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
Tucatinib is a strong CYP3A inhibitor and may increase irinotecan and SN-38 exposure. This can worsen severe diarrhea and myelosuppression. Tucatinib itself commonly causes diarrhea, which compounds the problem.
What this interaction means in plain words
Irinotecan and Tucatinib 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.
Irinotecan belongs to Oncology; Tucatinib belongs to Oncology.
Why it happens
Tucatinib inhibits CYP3A4, reducing irinotecan oxidative clearance.
What to do
Avoid concurrent use where possible. If necessary, monitor for diarrhea and neutropenia and consider reducing the irinotecan dose.
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 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
Other interactions of Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Irinotecan with Tucatinib?
MediHelp rates the interaction as major. Irinotecan and Tucatinib 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. Tucatinib is a strong CYP3A inhibitor and may increase irinotecan and SN-38 exposure. This can worsen severe diarrhea and myelosuppression. Tucatinib itself commonly causes diarrhea, which compounds the problem.
How serious is the interaction between Irinotecan and Tucatinib?
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 concurrent use where possible. If necessary, monitor for diarrhea and neutropenia and consider reducing the irinotecan dose.
What other medicines interact with Irinotecan?
MediHelp also lists interactions of Irinotecan with, for example, Clozapine, Sacituzumab govitecan, Adenovirus types 4 and 7 live. The full list is on the Irinotecan page.
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