Drug interactions
Dolasetron + Trimethoprim
Severity: Moderate
Dolasetron and Trimethoprim: 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
Dolasetron's metabolite prolongs cardiac conduction intervals including QT. Trimethoprim, particularly as co-trimoxazole, has been rarely associated with QT prolongation, so additive effects are possible. The clinical significance is likely small in patients without other risk factors.
What this interaction means in plain words
Dolasetron and Trimethoprim 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.
Dolasetron belongs to Gastrointestinal Tract; Trimethoprim belongs to Anti Bacterial.
Why it happens
Possible additive effect on ventricular repolarization; trimethoprim's QT effect is poorly established.
What to do
Check and correct potassium and magnesium, and consider an ECG in patients with cardiac disease or other QT-prolonging drugs. Choose 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 Dolasetron
- Apomorphine + Dolasetron Contraindicated
- Dofetilide + Dolasetron Contraindicated
- Dolasetron + Ibutilide Contraindicated
- Dolasetron + Pimozide Contraindicated
- Dolasetron + Thioridazine Contraindicated
- Dolasetron + Vandetanib Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Dolasetron with Trimethoprim?
MediHelp rates the interaction as moderate. Dolasetron and Trimethoprim 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. Dolasetron's metabolite prolongs cardiac conduction intervals including QT. Trimethoprim, particularly as co-trimoxazole, has been rarely associated with QT prolongation, so additive effects are possible. The clinical significance is likely small in patients without other risk factors.
How serious is the interaction between Dolasetron and Trimethoprim?
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 and correct potassium and magnesium, and consider an ECG in patients with cardiac disease or other QT-prolonging drugs. Choose an alternative antiemetic in high-risk patients.
What other medicines interact with Dolasetron?
MediHelp also lists interactions of Dolasetron with, for example, Apomorphine, Dofetilide, Ibutilide. The full list is on the Dolasetron page.
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