Drug interactions
Clarithromycin + Irinotecan
Severity: Major
Clarithromycin 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
Clarithromycin inhibits CYP3A4 and P-glycoprotein, which may increase exposure to irinotecan and its active metabolite SN-38 by diverting it away from inactive pathways. This may worsen neutropenia and diarrhea.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Irinotecan belongs to Oncology.
Why it happens
CYP3A4 and P-glycoprotein inhibition by clarithromycin alters irinotecan disposition and increases toxic exposure.
What to do
Choose a non-interacting antibiotic where possible. If clarithromycin is required, monitor closely for severe diarrhea and myelosuppression and adjust irinotecan as needed.
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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine 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 Clarithromycin with Irinotecan?
MediHelp rates the interaction as major. Clarithromycin 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. Clarithromycin inhibits CYP3A4 and P-glycoprotein, which may increase exposure to irinotecan and its active metabolite SN-38 by diverting it away from inactive pathways. This may worsen neutropenia and diarrhea.
How serious is the interaction between Clarithromycin 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: Choose a non-interacting antibiotic where possible. If clarithromycin is required, monitor closely for severe diarrhea and myelosuppression and adjust irinotecan as needed.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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