Drug interactions
Ondansetron + Verapamil
Severity: Minor
Ondansetron and Verapamil: 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
Verapamil inhibits CYP3A4 and may reduce ondansetron clearance. Because ondansetron is cleared by several enzymes, any increase in exposure is expected to be small, though both agents can affect cardiac conduction.
What this interaction means in plain words
Ondansetron and Verapamil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Ondansetron belongs to Gastrointestinal Tract; Verapamil belongs to Cardiovascular.
Why it happens
Verapamil inhibits CYP3A4 (and possibly CYP1A2), reducing one part of ondansetron metabolism.
What to do
No dose adjustment is usually needed. Monitor heart rate and ECG in patients with conduction disease or other QT risk factors.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Ondansetron and Verapamil, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Frequently asked questions
Can I take Ondansetron with Verapamil?
MediHelp rates the interaction as minor. Ondansetron and Verapamil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Verapamil inhibits CYP3A4 and may reduce ondansetron clearance. Because ondansetron is cleared by several enzymes, any increase in exposure is expected to be small, though both agents can affect cardiac conduction.
How serious is the interaction between Ondansetron and Verapamil?
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 usually needed. Monitor heart rate and ECG in patients with conduction disease or other QT risk factors.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
