Drug interactions
Erythromycin + Irinotecan
Severity: Major
Erythromycin and Irinotecan: 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
Erythromycin may increase exposure to irinotecan and its active metabolite SN-38, raising the risk of severe diarrhea and myelosuppression. The effect is predicted from CYP3A4 inhibition.
What this interaction means in plain words
Erythromycin 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.
Erythromycin belongs to Anti Bacterial; Irinotecan belongs to Oncology.
Why it happens
Erythromycin inhibits CYP3A4, which converts irinotecan to inactive metabolites, so more drug is available for conversion to SN-38.
What to do
Use a non-CYP3A4-inhibiting antibiotic where possible. If unavoidable, monitor closely 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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References
Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin 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 Erythromycin with Irinotecan?
MediHelp rates the interaction as major. Erythromycin 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. Erythromycin may increase exposure to irinotecan and its active metabolite SN-38, raising the risk of severe diarrhea and myelosuppression. The effect is predicted from CYP3A4 inhibition.
How serious is the interaction between Erythromycin 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: Use a non-CYP3A4-inhibiting antibiotic where possible. If unavoidable, monitor closely for diarrhea and neutropenia and consider reducing the irinotecan dose.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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