Drug interactions
Fentanyl transmucosal + Posaconazole
Severity: Major
Fentanyl transmucosal and Posaconazole: 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
Posaconazole can substantially raise fentanyl concentrations, particularly the swallowed fraction absorbed through the gut. This can cause profound sedation and potentially fatal respiratory depression.
What this interaction means in plain words
Fentanyl transmucosal and Posaconazole 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
Strong CYP3A4 inhibition in gut and liver reduces fentanyl clearance.
What to do
Avoid if possible or use a non-CYP3A4-dependent opioid. If unavoidable, monitor closely 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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Frequently asked questions
Can I take Fentanyl transmucosal with Posaconazole?
MediHelp rates the interaction as major. Fentanyl transmucosal and Posaconazole 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. Posaconazole can substantially raise fentanyl concentrations, particularly the swallowed fraction absorbed through the gut. This can cause profound sedation and potentially fatal respiratory depression.
How serious is the interaction between Fentanyl transmucosal and Posaconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible or use a non-CYP3A4-dependent opioid. If unavoidable, monitor closely for respiratory depression and sedation and reduce the fentanyl dose.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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