Drug interactions
Dosulepin + Venlafaxine
Severity: Major
Dosulepin and Venlafaxine: 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 agents increase synaptic serotonin, and combined use raises the risk of serotonin syndrome. Dosulepin is a tricyclic whose levels may also rise because venlafaxine weakly inhibits CYP2D6, and tricyclics add cardiac and seizure risks.
What this interaction means in plain words
Dosulepin and Venlafaxine 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; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive serotonergic effects, plus possible CYP2D6-mediated increase in tricyclic exposure.
What to do
Avoid the combination where possible. If used, start at low doses, titrate slowly, monitor for serotonin toxicity and cardiac effects, and consider tricyclic levels or an ECG.
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 Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine 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 Venlafaxine?
MediHelp rates the interaction as major. Dosulepin and Venlafaxine 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 agents increase synaptic serotonin, and combined use raises the risk of serotonin syndrome. Dosulepin is a tricyclic whose levels may also rise because venlafaxine weakly inhibits CYP2D6, and tricyclics add cardiac and seizure risks.
How serious is the interaction between Dosulepin and Venlafaxine?
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 the combination where possible. If used, start at low doses, titrate slowly, monitor for serotonin toxicity and cardiac effects, and consider tricyclic levels or an ECG.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Venlafaxine page.
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