Drug interactions
Irinotecan + Istradefylline
Severity: Moderate
Irinotecan and Istradefylline: 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
At 40 mg/day istradefylline increases exposure to CYP3A4 and P-gp substrates, and could therefore raise irinotecan and SN-38 exposure. This may worsen diarrhea and myelosuppression. The effect was not seen at 20 mg/day.
What this interaction means in plain words
Irinotecan and Istradefylline 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; Istradefylline belongs to Central Nervous System.
Why it happens
Istradefylline inhibits CYP3A4 and P-gp at higher doses, decreasing irinotecan clearance and efflux.
What to do
Keep istradefylline at 20 mg/day if possible and monitor blood counts and diarrhea; reduce irinotecan dose if toxicity occurs.
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 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 Istradefylline
Frequently asked questions
Can I take Irinotecan with Istradefylline?
MediHelp rates the interaction as moderate. Irinotecan and Istradefylline 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. At 40 mg/day istradefylline increases exposure to CYP3A4 and P-gp substrates, and could therefore raise irinotecan and SN-38 exposure. This may worsen diarrhea and myelosuppression. The effect was not seen at 20 mg/day.
How serious is the interaction between Irinotecan and Istradefylline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Keep istradefylline at 20 mg/day if possible and monitor blood counts and diarrhea; reduce irinotecan dose if toxicity occurs.
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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