Does Ondansetron Interact with Amiodarone?
Ondansetron and Amiodarone have a major drug interaction according to established clinical references. Both ondansetron and amiodarone prolong the QT interval; used together they raise the risk of QT prolongation and torsades de pointes. Avoid the combination in patients with additional QT risk factors (electrolyte disturbance, bradycardia, other QT-prolonging drugs). The mechanism involves additive blockade of the cardiac herg (ikr) potassium channel prolongs ventricular repolarization. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is drawn from established clinical references and is provided alongside our FDA-labeling–based data.
- Severity
- Major
- Ondansetron Class
- Serotonin-3 Receptor Antagonist
- Management
- Close medical supervision required
- Data Source
- Curated clinical reference
How This Interaction Works
The interaction between Ondansetron and Amiodarone occurs because additive blockade of the cardiac herg (ikr) potassium channel prolongs ventricular repolarization. Clinically, this means both ondansetron and amiodarone prolong the qt interval; used together they raise the risk of qt prolongation and torsades de pointes. avoid the combination in patients with additional qt risk factors (electrolyte disturbance, bradycardia, other qt-prolonging drugs). This is classified as a major interaction, meaning it could cause serious harm if not properly managed. Your healthcare provider may need to adjust dosages, substitute one medication, or increase monitoring frequency.
What To Tell Your Doctor or Pharmacist
If you are taking Ondansetron and your doctor is considering prescribing Amiodarone (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider