Drug interactions
Clarithromycin + Fentanyl transdermal
Severity: Major
Clarithromycin and Fentanyl transdermal: 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 can substantially raise fentanyl concentrations, risking profound sedation and potentially fatal respiratory depression. With transdermal systems the effect develops gradually and may persist after the inhibitor is stopped, because of the skin depot.
What this interaction means in plain words
Clarithromycin and Fentanyl transdermal 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
Clarithromycin inhibits CYP3A4, the main pathway of fentanyl clearance.
What to do
Prefer a non-interacting antibiotic such as azithromycin. If it cannot be avoided, monitor closely for respiratory depression and sedation and reduce the fentanyl dose, continuing monitoring after clarithromycin is stopped.
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
Frequently asked questions
Can I take Clarithromycin with Fentanyl transdermal?
MediHelp rates the interaction as major. Clarithromycin and Fentanyl transdermal 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 can substantially raise fentanyl concentrations, risking profound sedation and potentially fatal respiratory depression. With transdermal systems the effect develops gradually and may persist after the inhibitor is stopped, because of the skin depot.
How serious is the interaction between Clarithromycin and Fentanyl transdermal?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-interacting antibiotic such as azithromycin. If it cannot be avoided, monitor closely for respiratory depression and sedation and reduce the fentanyl dose, continuing monitoring after clarithromycin is stopped.
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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