Drug interactions
Isocarboxazid + Phentermine
Severity: Contraindicated
Isocarboxazid and Phentermine: 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 given with an MAOI may cause severe hypertension and hypertensive crisis. The risk persists for about two weeks after the MAOI is stopped.
What this interaction means in plain words
Isocarboxazid and Phentermine 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.
Isocarboxazid belongs to Central Nervous System; Phentermine belongs to Central Nervous System.
Why it happens
Phentermine promotes noradrenaline release while MAO inhibition prevents its degradation.
What to do
Do not use together or within 14 days of stopping isocarboxazid.
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 Isocarboxazid
- 5-HTP + Isocarboxazid Contraindicated
- Amitriptyline + Isocarboxazid Contraindicated
- Amobarbital + Isocarboxazid Contraindicated
- Amoxapine + Isocarboxazid Contraindicated
- Apraclonidine + Isocarboxazid Contraindicated
- Atomoxetine + Isocarboxazid Contraindicated
Other interactions of Phentermine
- Linezolid + Phentermine Contraindicated
- Phenelzine + Phentermine Contraindicated
- Phentermine + Procarbazine Contraindicated
- Phentermine + Rasagiline Contraindicated
- Phentermine + Selegiline Contraindicated
- Phentermine + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Isocarboxazid with Phentermine?
MediHelp rates the interaction as contraindicated. Isocarboxazid and Phentermine 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 given with an MAOI may cause severe hypertension and hypertensive crisis. The risk persists for about two weeks after the MAOI is stopped.
How serious is the interaction between Isocarboxazid and Phentermine?
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 use together or within 14 days of stopping isocarboxazid.
What other medicines interact with Isocarboxazid?
MediHelp also lists interactions of Isocarboxazid with, for example, 5-HTP, Amitriptyline, Amobarbital. The full list is on the Isocarboxazid page.
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