Drug interactions
Phentermine + Tranylcypromine
Severity: Contraindicated
Phentermine and Tranylcypromine: 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
Phentermine is an indirect sympathomimetic, and with an MAO inhibitor it can cause hypertensive crisis. Labeling advises against use during or within 14 days of MAOI therapy.
What this interaction means in plain words
Phentermine and Tranylcypromine 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.
Phentermine belongs to Central Nervous System; Tranylcypromine belongs to Central Nervous System.
Why it happens
Phentermine releases norepinephrine while MAO inhibition prevents its metabolism, causing an exaggerated pressor response.
What to do
Do not co-administer. Allow at least 14 days after stopping tranylcypromine before starting phentermine.
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 Tranylcypromine
- 5-HTP + Tranylcypromine Contraindicated
- Amitriptyline + Tranylcypromine Contraindicated
- Amoxapine + Tranylcypromine Contraindicated
- Atomoxetine + Tranylcypromine Contraindicated
- Benzphetamine + Tranylcypromine Contraindicated
- Brimonidine + Tranylcypromine Contraindicated
Other interactions of Phentermine
- Isocarboxazid + Phentermine Contraindicated
- Linezolid + Phentermine Contraindicated
- Phenelzine + Phentermine Contraindicated
- Phentermine + Procarbazine Contraindicated
- Phentermine + Rasagiline Contraindicated
- Phentermine + Selegiline Contraindicated
Frequently asked questions
Can I take Phentermine with Tranylcypromine?
MediHelp rates the interaction as contraindicated. Phentermine and Tranylcypromine 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. Phentermine is an indirect sympathomimetic, and with an MAO inhibitor it can cause hypertensive crisis. Labeling advises against use during or within 14 days of MAOI therapy.
How serious is the interaction between Phentermine and Tranylcypromine?
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 co-administer. Allow at least 14 days after stopping tranylcypromine before starting phentermine.
What other medicines interact with Tranylcypromine?
MediHelp also lists interactions of Tranylcypromine with, for example, 5-HTP, Amitriptyline, Amoxapine. The full list is on the Tranylcypromine page.
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