Drug interactions
Fentanyl transmucosal + Methadone
Severity: Major
Fentanyl transmucosal and Methadone: 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
Taking methadone with transmucosal fentanyl increases the chance of profound sedation, respiratory depression, hypotension and death. The rapid onset of transmucosal fentanyl on top of methadone's long action makes overdose easier.
What this interaction means in plain words
Fentanyl transmucosal and Methadone 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
Additive mu-opioid receptor mediated CNS and respiratory depression.
What to do
Use only if alternatives are inadequate, with the lowest effective doses. Monitor for sedation and respiratory depression and make naloxone available.
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 Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Frequently asked questions
Can I take Fentanyl transmucosal with Methadone?
MediHelp rates the interaction as major. Fentanyl transmucosal and Methadone 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. Taking methadone with transmucosal fentanyl increases the chance of profound sedation, respiratory depression, hypotension and death. The rapid onset of transmucosal fentanyl on top of methadone's long action makes overdose easier.
How serious is the interaction between Fentanyl transmucosal and Methadone?
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 only if alternatives are inadequate, with the lowest effective doses. Monitor for sedation and respiratory depression and make naloxone available.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
Full monographs, dosing and an interaction checker in the MediHelp app
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