Drug interactions
Droperidol + Ondansetron
Severity: Major
Droperidol and Ondansetron: major interaction.
Last updated Sources: UK SmPC
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
Droperidol carries a boxed warning for QT prolongation and torsades de pointes, and ondansetron adds to this effect. Using both, as sometimes occurs for postoperative nausea, raises the arrhythmia risk.
What this interaction means in plain words
Droperidol and Ondansetron 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.
Why it happens
Additive QT prolongation through blockade of hERG potassium channels.
What to do
Avoid combining them in patients with QT risk factors and use an antiemetic with less QT effect. If both are used, monitor the ECG and correct potassium and magnesium.
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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References
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 Droperidol with Ondansetron?
MediHelp rates the interaction as major. Droperidol and Ondansetron 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. Droperidol carries a boxed warning for QT prolongation and torsades de pointes, and ondansetron adds to this effect. Using both, as sometimes occurs for postoperative nausea, raises the arrhythmia risk.
How serious is the interaction between Droperidol and Ondansetron?
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 combining them in patients with QT risk factors and use an antiemetic with less QT effect. If both are used, monitor the ECG and correct potassium and magnesium.
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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