Drug interactions
Irinotecan + Posaconazole
Severity: Major
Irinotecan and Posaconazole: major interaction.
Last updated Sources: US FDA label
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
Irinotecan and its active metabolite SN-38 are affected by CYP3A4, and strong inhibitors can alter exposure to them. Posaconazole may reduce formation of inactive metabolites and increase SN-38, raising the risk of severe diarrhea and neutropenia.
What this interaction means in plain words
Irinotecan and Posaconazole 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; Posaconazole belongs to Anti Fungals.
Why it happens
Posaconazole inhibits CYP3A4, altering irinotecan metabolism and increasing SN-38 exposure.
What to do
Avoid strong CYP3A4 inhibitors during irinotecan therapy where possible. If used together, monitor for diarrhea and neutropenia and consider an 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 Irinotecan and Posaconazole, 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.
References
Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
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 Posaconazole?
MediHelp rates the interaction as major. Irinotecan and Posaconazole 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 and its active metabolite SN-38 are affected by CYP3A4, and strong inhibitors can alter exposure to them. Posaconazole may reduce formation of inactive metabolites and increase SN-38, raising the risk of severe diarrhea and neutropenia.
How serious is the interaction between Irinotecan and Posaconazole?
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 strong CYP3A4 inhibitors during irinotecan therapy where possible. If used together, monitor for diarrhea and neutropenia and consider an irinotecan dose reduction.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole 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.
