Drug interactions
Fentanyl intranasal + Methadone
Severity: Major
Fentanyl intranasal 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
Combining two opioids increases the risk of profound sedation, respiratory depression, hypotension, coma and death. Methadone's long and variable half-life makes the combined effect hard to predict.
What this interaction means in plain words
Fentanyl intranasal 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 pharmacodynamic CNS and respiratory depression through mu-opioid receptor agonism.
What to do
Reserve the combination for patients with inadequate alternatives, using the lowest effective doses and shortest duration. Monitor closely for sedation and respiratory depression and consider naloxone availability.
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 intranasal with Methadone?
MediHelp rates the interaction as major. Fentanyl intranasal 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. Combining two opioids increases the risk of profound sedation, respiratory depression, hypotension, coma and death. Methadone's long and variable half-life makes the combined effect hard to predict.
How serious is the interaction between Fentanyl intranasal 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: Reserve the combination for patients with inadequate alternatives, using the lowest effective doses and shortest duration. Monitor closely for sedation and respiratory depression and consider naloxone availability.
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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