Drug interactions
Isocarboxazid + Ondansetron
Severity: Major
Isocarboxazid and Ondansetron: 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
Ondansetron has been associated with serotonin syndrome when given with serotonergic drugs, and an MAO inhibitor greatly raises the vulnerability to this. The combination could produce severe neuromuscular, autonomic and mental status changes.
What this interaction means in plain words
Isocarboxazid and Ondansetron 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.
Isocarboxazid belongs to Central Nervous System; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Additive serotonergic effects, with MAO inhibition preventing serotonin breakdown.
What to do
Prefer an antiemetic that is not serotonergic, such as one from another class that is MAOI-compatible. If used, give the lowest dose and monitor closely for serotonin syndrome.
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 Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
Other interactions of Isocarboxazid
- 5-HTP + Isocarboxazid Contraindicated
- Amitriptyline + Isocarboxazid Contraindicated
- Amobarbital + Isocarboxazid Contraindicated
- Amoxapine + Isocarboxazid Contraindicated
- Apraclonidine + Isocarboxazid Contraindicated
- Atomoxetine + Isocarboxazid Contraindicated
Frequently asked questions
Can I take Isocarboxazid with Ondansetron?
MediHelp rates the interaction as major. Isocarboxazid and Ondansetron 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. Ondansetron has been associated with serotonin syndrome when given with serotonergic drugs, and an MAO inhibitor greatly raises the vulnerability to this. The combination could produce severe neuromuscular, autonomic and mental status changes.
How serious is the interaction between Isocarboxazid and Ondansetron?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an antiemetic that is not serotonergic, such as one from another class that is MAOI-compatible. If used, give the lowest dose and monitor closely for serotonin syndrome.
What other medicines interact with Ondansetron?
MediHelp also lists interactions of Ondansetron with, for example, Apomorphine, Thioridazine, Vandetanib. The full list is on the Ondansetron page.
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