Drug interactions
Erythromycin + Fentanyl transmucosal
Severity: Major
Erythromycin and Fentanyl transmucosal: 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
Erythromycin inhibits CYP3A4, the main pathway clearing fentanyl, and can raise fentanyl levels. This may cause profound sedation and potentially fatal respiratory depression.
What this interaction means in plain words
Erythromycin and Fentanyl transmucosal 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.
Why it happens
CYP3A4 inhibition reduces fentanyl clearance and raises plasma concentrations.
What to do
Use an alternative antibiotic where possible. If combined, monitor closely for sedation and respiratory depression and lower the fentanyl dose 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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Frequently asked questions
Can I take Erythromycin with Fentanyl transmucosal?
MediHelp rates the interaction as major. Erythromycin and Fentanyl transmucosal 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 inhibits CYP3A4, the main pathway clearing fentanyl, and can raise fentanyl levels. This may cause profound sedation and potentially fatal respiratory depression.
How serious is the interaction between Erythromycin and Fentanyl transmucosal?
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 an alternative antibiotic where possible. If combined, monitor closely for sedation and respiratory depression and lower the fentanyl dose as needed.
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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