Drug interactions
Dosulepin + Methadone
Severity: Major
Dosulepin and Methadone: major interaction.
Last updated Sources: US FDA label
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
Both drugs cause sedation, and dosulepin, a tricyclic antidepressant, adds anticholinergic effects and may prolong the QT interval. Combined use raises the risk of respiratory depression, arrhythmia and, rarely, serotonergic toxicity.
What this interaction means in plain words
Dosulepin 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.
Dosulepin belongs to Central Nervous System; Methadone belongs to Musculoskeletal.
Why it happens
Additive CNS depression and QT prolongation, with possible serotonergic contribution and CYP2D6 inhibition by tricyclics.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes, using the lowest effective doses. Monitor for sedation and signs of serotonin toxicity.
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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References
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
Other interactions of Dosulepin
- Dosulepin + Isocarboxazid Contraindicated
- Dosulepin + Phenelzine Contraindicated
- Dosulepin + Thioridazine Contraindicated
- Dosulepin + Tranylcypromine Contraindicated
- Amitriptyline + Dosulepin Major
- Buprenorphine + Dosulepin Major
Frequently asked questions
Can I take Dosulepin with Methadone?
MediHelp rates the interaction as major. Dosulepin 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. Both drugs cause sedation, and dosulepin, a tricyclic antidepressant, adds anticholinergic effects and may prolong the QT interval. Combined use raises the risk of respiratory depression, arrhythmia and, rarely, serotonergic toxicity.
How serious is the interaction between Dosulepin 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: Obtain a baseline ECG and monitor QTc and electrolytes, using the lowest effective doses. Monitor for sedation and signs of serotonin toxicity.
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.
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