Drug interactions
Clarithromycin + Fentanyl intranasal
Severity: Major
Clarithromycin and Fentanyl intranasal: 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. The risk persists for the duration of inhibition, and effects can intensify after the inhibitor is started.
What this interaction means in plain words
Clarithromycin and Fentanyl intranasal 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, including first-pass metabolism of swallowed drug.
What to do
Prefer a non-interacting antibiotic such as azithromycin. If it cannot be avoided, monitor frequently for respiratory depression and sedation and reduce the fentanyl 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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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 intranasal?
MediHelp rates the interaction as major. Clarithromycin and Fentanyl intranasal 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. The risk persists for the duration of inhibition, and effects can intensify after the inhibitor is started.
How serious is the interaction between Clarithromycin and Fentanyl intranasal?
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 frequently for respiratory depression and sedation and reduce the fentanyl dose.
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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