Drug interactions
Ondansetron + Propafenone
Severity: Major
Ondansetron and Propafenone: 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
Propafenone can prolong QRS and QT intervals and is proarrhythmic, and ondansetron adds a QT-prolonging effect. Together they may increase the risk of serious ventricular arrhythmias, especially in structural heart disease.
What this interaction means in plain words
Ondansetron and Propafenone 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 belongs to Gastrointestinal Tract; Propafenone belongs to Cardiovascular.
Why it happens
Additive cardiac repolarization delay; propafenone also blocks sodium channels and may increase ondansetron exposure through CYP2D6 inhibition.
What to do
Avoid the combination where possible and use a different antiemetic. If used together, check electrolytes and monitor the ECG.
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 Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone Contraindicated
Frequently asked questions
Can I take Ondansetron with Propafenone?
MediHelp rates the interaction as major. Ondansetron and Propafenone 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. Propafenone can prolong QRS and QT intervals and is proarrhythmic, and ondansetron adds a QT-prolonging effect. Together they may increase the risk of serious ventricular arrhythmias, especially in structural heart disease.
How serious is the interaction between Ondansetron and Propafenone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use a different antiemetic. If used together, check electrolytes and monitor the ECG.
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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