Drug interactions
Phenelzine + Tyramine
Severity: Contraindicated
Phenelzine and Tyramine: 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
Dietary tyramine is normally broken down by MAO in the gut and liver. With MAO inhibited, it enters the circulation and displaces norepinephrine from nerve terminals, causing severe hypertensive crisis with headache and risk of stroke.
What this interaction means in plain words
Phenelzine and Tyramine 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.
Why it happens
Loss of gastrointestinal and hepatic MAO-A metabolism permits systemic tyramine to release norepinephrine.
What to do
Instruct patients to follow a low-tyramine diet during and for 2 weeks after phenelzine. Treat a hypertensive crisis as an emergency with urgent blood pressure lowering.
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 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 Tyramine?
MediHelp rates the interaction as contraindicated. Phenelzine and Tyramine 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. Dietary tyramine is normally broken down by MAO in the gut and liver. With MAO inhibited, it enters the circulation and displaces norepinephrine from nerve terminals, causing severe hypertensive crisis with headache and risk of stroke.
How serious is the interaction between Phenelzine and Tyramine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Instruct patients to follow a low-tyramine diet during and for 2 weeks after phenelzine. Treat a hypertensive crisis as an emergency with urgent blood pressure lowering.
What other medicines interact with Phenelzine?
MediHelp also lists interactions of Phenelzine with, for example, 5-HTP, Amitriptyline, Amoxapine. The full list is on the Phenelzine page.
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