Drug interactions
Ondansetron + Trimipramine
Severity: Moderate
Ondansetron and Trimipramine: 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
Trimipramine can prolong the QT interval and has serotonergic activity, and ondansetron has the same QT effect and has been linked to serotonin syndrome. Together they add arrhythmia risk and a modest risk of serotonin toxicity.
What this interaction means in plain words
Ondansetron and Trimipramine 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; Trimipramine belongs to Central Nervous System.
Why it happens
Additive QT prolongation plus possible additive serotonergic effects.
What to do
Check an ECG and correct potassium and magnesium when combining, especially with intravenous ondansetron or other risk factors. Watch for serotonin toxicity and consider an alternative antiemetic in high-risk patients.
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 Trimipramine
- Disopyramide + Trimipramine Contraindicated
- Dofetilide + Trimipramine Contraindicated
- Ibutilide + Trimipramine Contraindicated
- Isocarboxazid + Trimipramine Contraindicated
- Pentamidine + Trimipramine Contraindicated
- Phenelzine + Trimipramine Contraindicated
Frequently asked questions
Can I take Ondansetron with Trimipramine?
MediHelp rates the interaction as moderate. Ondansetron and Trimipramine 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. Trimipramine can prolong the QT interval and has serotonergic activity, and ondansetron has the same QT effect and has been linked to serotonin syndrome. Together they add arrhythmia risk and a modest risk of serotonin toxicity.
How serious is the interaction between Ondansetron and Trimipramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check an ECG and correct potassium and magnesium when combining, especially with intravenous ondansetron or other risk factors. Watch for serotonin toxicity and consider an alternative antiemetic in high-risk patients.
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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