Drug interactions
Pimozide + Trimethoprim
Severity: Moderate
Pimozide 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
Trimethoprim has been linked to QT prolongation in some reports and may add to the strong QT effect of pimozide. The combined risk of torsades de pointes is higher in patients with electrolyte disturbance or hyperkalemia.
What this interaction means in plain words
Pimozide 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.
Pimozide belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Possible additive QT prolongation; evidence is limited.
What to do
Use an alternative antibacterial if possible. If combined, monitor ECG, potassium and magnesium.
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 Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Pimozide with Trimethoprim?
MediHelp rates the interaction as moderate. Pimozide 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. Trimethoprim has been linked to QT prolongation in some reports and may add to the strong QT effect of pimozide. The combined risk of torsades de pointes is higher in patients with electrolyte disturbance or hyperkalemia.
How serious is the interaction between Pimozide 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: Use an alternative antibacterial if possible. If combined, monitor ECG, potassium and magnesium.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
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