Drug interactions
Haloperidol + Trimethoprim
Severity: Moderate
Haloperidol 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
Both drugs have been linked to QT prolongation, so concurrent use may add to arrhythmia risk. The risk is greatest with electrolyte disturbances, renal impairment or additional QT-prolonging drugs.
What this interaction means in plain words
Haloperidol 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.
Haloperidol belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Additive prolongation of ventricular repolarization.
What to do
Check electrolytes and consider a baseline ECG in at-risk patients. Monitor for hyperkalemia and QTc changes, and choose an alternative antibiotic if risk is high.
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 Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Haloperidol with Trimethoprim?
MediHelp rates the interaction as moderate. Haloperidol 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. Both drugs have been linked to QT prolongation, so concurrent use may add to arrhythmia risk. The risk is greatest with electrolyte disturbances, renal impairment or additional QT-prolonging drugs.
How serious is the interaction between Haloperidol 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 electrolytes and consider a baseline ECG in at-risk patients. Monitor for hyperkalemia and QTc changes, and choose an alternative antibiotic if risk is high.
What other medicines interact with Haloperidol?
MediHelp also lists interactions of Haloperidol with, for example, Dofetilide, Dronedarone, Ibutilide. The full list is on the Haloperidol page.
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