Drug interactions
Phenelzine + Venlafaxine
Severity: Contraindicated
Phenelzine and Venlafaxine: contraindicated 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
Venlafaxine with phenelzine can cause life-threatening serotonin syndrome, with hyperthermia, rigidity, autonomic instability and seizures. The combination is contraindicated in labeling.
What this interaction means in plain words
Phenelzine and Venlafaxine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Phenelzine belongs to Central Nervous System; Venlafaxine belongs to Central Nervous System.
Why it happens
Serotonin and noradrenaline reuptake inhibition combined with irreversible MAO inhibition causes monoamine excess.
What to do
Do not coadminister. Leave at least 14 days after stopping phenelzine before starting venlafaxine, and at least 7 days after stopping venlafaxine before starting phenelzine.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
- Selegiline transdermal + Venlafaxine Contraindicated
Other interactions of Phenelzine
- 5-HTP + Phenelzine Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amoxapine + Phenelzine Contraindicated
- Atomoxetine + Phenelzine Contraindicated
- Benzphetamine + Phenelzine Contraindicated
- Brimonidine + Phenelzine Contraindicated
Frequently asked questions
Can I take Phenelzine with Venlafaxine?
MediHelp rates the interaction as contraindicated. Phenelzine and Venlafaxine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Venlafaxine with phenelzine can cause life-threatening serotonin syndrome, with hyperthermia, rigidity, autonomic instability and seizures. The combination is contraindicated in labeling.
How serious is the interaction between Phenelzine and Venlafaxine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not coadminister. Leave at least 14 days after stopping phenelzine before starting venlafaxine, and at least 7 days after stopping venlafaxine before starting phenelzine.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Methylene blue, Procarbazine. The full list is on the Venlafaxine page.
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