Drug interactions
Conivaptan + Ondansetron
Severity: Minor
Conivaptan 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
Conivaptan is a CYP3A4 inhibitor and could raise ondansetron concentrations. Since ondansetron has several clearance pathways, the increase is likely to be modest.
What this interaction means in plain words
Conivaptan 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.
Why it happens
Inhibition of CYP3A4 by conivaptan reduces one pathway of ondansetron metabolism.
What to do
No routine dose change is needed. Monitor for QT-related effects if other risk factors for QT prolongation 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
Frequently asked questions
Can I take Conivaptan with Ondansetron?
MediHelp rates the interaction as minor. Conivaptan 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. Conivaptan is a CYP3A4 inhibitor and could raise ondansetron concentrations. Since ondansetron has several clearance pathways, the increase is likely to be modest.
How serious is the interaction between Conivaptan 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 routine dose change is needed. Monitor for QT-related effects if other risk factors for QT prolongation 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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