Drug interactions
Nefazodone + Venlafaxine
Severity: Major
Nefazodone and Venlafaxine: 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
Nefazodone inhibits serotonin reuptake and is a strong CYP3A4 inhibitor, which may raise venlafaxine exposure. The combination raises the risk of serotonin syndrome, and nefazodone also carries a hepatotoxicity risk.
What this interaction means in plain words
Nefazodone 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 serotonergic activity plus CYP3A4 inhibition.
What to do
Avoid combining the two antidepressants. If the switch is necessary, allow a washout and monitor for serotonin toxicity and blood pressure changes.
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 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 Nefazodone with Venlafaxine?
MediHelp rates the interaction as major. Nefazodone 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. Nefazodone inhibits serotonin reuptake and is a strong CYP3A4 inhibitor, which may raise venlafaxine exposure. The combination raises the risk of serotonin syndrome, and nefazodone also carries a hepatotoxicity risk.
How serious is the interaction between Nefazodone 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 combining the two antidepressants. If the switch is necessary, allow a washout and monitor for serotonin toxicity and blood pressure changes.
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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