Drug interactions
Ondansetron + Primaquine
Severity: Moderate
Ondansetron and Primaquine: 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
Primaquine can prolong the QT interval, and ondansetron has the same effect, so co-administration may add to the risk of arrhythmia. The clinical risk is greatest with cardiac disease or electrolyte disturbances.
What this interaction means in plain words
Ondansetron and Primaquine 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; Primaquine belongs to Anti Parasitic.
Why it happens
Additive effects on cardiac repolarization leading to QT prolongation.
What to do
Correct electrolyte abnormalities and obtain an ECG in patients with cardiac risk factors. Use the lowest effective ondansetron dose.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Frequently asked questions
Can I take Ondansetron with Primaquine?
MediHelp rates the interaction as moderate. Ondansetron and Primaquine 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. Primaquine can prolong the QT interval, and ondansetron has the same effect, so co-administration may add to the risk of arrhythmia. The clinical risk is greatest with cardiac disease or electrolyte disturbances.
How serious is the interaction between Ondansetron and Primaquine?
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 electrolyte abnormalities and obtain an ECG in patients with cardiac risk factors. Use the lowest effective ondansetron dose.
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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