Drug interactions
Ondansetron + Perphenazine
Severity: Moderate
Ondansetron and Perphenazine: moderate 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
Perphenazine and ondansetron both have the potential to prolong the QT interval, so combined use could increase the risk of torsades de pointes. The concern is higher in patients with underlying heart disease, bradycardia or low electrolytes.
What this interaction means in plain words
Ondansetron and Perphenazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Ondansetron belongs to Gastrointestinal Tract; Perphenazine belongs to Central Nervous System.
Why it happens
Additive delayed cardiac repolarization through hERG channel blockade.
What to do
Correct potassium and magnesium and use the lowest effective ondansetron dose. Obtain an ECG in patients with cardiac risk factors or other QT-prolonging drugs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Ondansetron with Perphenazine?
MediHelp rates the interaction as moderate. Ondansetron and Perphenazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Perphenazine and ondansetron both have the potential to prolong the QT interval, so combined use could increase the risk of torsades de pointes. The concern is higher in patients with underlying heart disease, bradycardia or low electrolytes.
How serious is the interaction between Ondansetron and Perphenazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Correct potassium and magnesium and use the lowest effective ondansetron dose. Obtain an ECG in patients with cardiac risk factors or other QT-prolonging drugs.
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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