Drug interactions
Isoniazid + Ondansetron
Severity: Minor
Isoniazid and Ondansetron: minor 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
Isoniazid inhibits CYP enzymes and could modestly raise ondansetron concentrations. Because ondansetron is cleared by multiple pathways, a clinically important change is unlikely.
What this interaction means in plain words
Isoniazid and Ondansetron have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Isoniazid belongs to Anti Bacterial; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Isoniazid inhibition of CYP3A4 and other CYP enzymes may slightly reduce ondansetron clearance.
What to do
No dose adjustment is needed; be aware of additive QT effects if other risk factors are present.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Isoniazid
Frequently asked questions
Can I take Isoniazid with Ondansetron?
MediHelp rates the interaction as minor. Isoniazid and Ondansetron have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Isoniazid inhibits CYP enzymes and could modestly raise ondansetron concentrations. Because ondansetron is cleared by multiple pathways, a clinically important change is unlikely.
How serious is the interaction between Isoniazid and Ondansetron?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is needed; be aware of additive QT effects if other risk factors are present.
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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