Drug interactions
Idelalisib + Irinotecan
Severity: Major
Idelalisib and Irinotecan: 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
Idelalisib is a strong CYP3A4 inhibitor and may raise irinotecan and SN-38 exposure. This could increase severe diarrhoea and neutropenia. Idelalisib itself causes diarrhoea and colitis, adding to the risk.
What this interaction means in plain words
Idelalisib and Irinotecan 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.
Idelalisib belongs to Oncology; Irinotecan belongs to Oncology.
Why it happens
CYP3A4 inhibition reduces conversion of irinotecan to inactive metabolites, together with additive gastrointestinal toxicity.
What to do
Avoid the combination if possible. If used, monitor closely for diarrhoea and neutropenia and consider irinotecan dose reduction.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Idelalisib and Irinotecan, 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 14 days on the web. No card needed.
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 Idelalisib
- Alfuzosin + Idelalisib Contraindicated
- Cisapride + Idelalisib Contraindicated
- Dihydroergotamine + Idelalisib Contraindicated
- Dronedarone + Idelalisib Contraindicated
- Eletriptan + Idelalisib Contraindicated
- Eplerenone + Idelalisib Contraindicated
Frequently asked questions
Can I take Idelalisib with Irinotecan?
MediHelp rates the interaction as major. Idelalisib and Irinotecan 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. Idelalisib is a strong CYP3A4 inhibitor and may raise irinotecan and SN-38 exposure. This could increase severe diarrhoea and neutropenia. Idelalisib itself causes diarrhoea and colitis, adding to the risk.
How serious is the interaction between Idelalisib and Irinotecan?
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 the combination if possible. If used, monitor closely for diarrhoea and neutropenia and consider irinotecan dose reduction.
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.
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.
