Drug interactions
Protriptyline + Venlafaxine
Severity: Major
Protriptyline 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 drugs inhibit monoamine reuptake, so together they can cause serotonin syndrome and noradrenergic effects such as tachycardia and hypertension. Venlafaxine may also inhibit CYP2D6 weakly, which can raise protriptyline levels and increase anticholinergic and cardiac toxicity.
What this interaction means in plain words
Protriptyline 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.
Why it happens
Additive serotonin and norepinephrine reuptake inhibition, plus possible CYP2D6 inhibition raising tricyclic exposure.
What to do
Avoid the combination where possible. If both are required, use low doses, monitor ECG, blood pressure and signs of serotonin toxicity, and consider protriptyline levels.
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
Frequently asked questions
Can I take Protriptyline with Venlafaxine?
MediHelp rates the interaction as major. Protriptyline 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 drugs inhibit monoamine reuptake, so together they can cause serotonin syndrome and noradrenergic effects such as tachycardia and hypertension. Venlafaxine may also inhibit CYP2D6 weakly, which can raise protriptyline levels and increase anticholinergic and cardiac toxicity.
How serious is the interaction between Protriptyline 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 both are required, use low doses, monitor ECG, blood pressure and signs of serotonin toxicity, and consider protriptyline levels.
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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