Drug interactions
Metronidazole + Pimozide
Severity: Contraindicated
Metronidazole and Pimozide: contraindicated 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
Pimozide prolongs the QT interval, and metronidazole has been associated with QT prolongation and possibly raises pimozide exposure. Together they increase the risk of torsades de pointes and other serious ventricular arrhythmias.
What this interaction means in plain words
Metronidazole and Pimozide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Metronidazole belongs to Anti Parasitic; Pimozide belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with possible metronidazole-mediated inhibition of pimozide metabolism.
What to do
Avoid the combination and choose an alternative antimicrobial. If unavoidable, obtain a baseline ECG, correct electrolytes and monitor QTc closely.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Metronidazole
- Ethanol + Metronidazole Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
- Lonafarnib + Metronidazole Major
Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Frequently asked questions
Can I take Metronidazole with Pimozide?
MediHelp rates the interaction as contraindicated. Metronidazole and Pimozide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Pimozide prolongs the QT interval, and metronidazole has been associated with QT prolongation and possibly raises pimozide exposure. Together they increase the risk of torsades de pointes and other serious ventricular arrhythmias.
How serious is the interaction between Metronidazole and Pimozide?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and choose an alternative antimicrobial. If unavoidable, obtain a baseline ECG, correct electrolytes and monitor QTc closely.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Amiodarone, Disulfiram. The full list is on the Metronidazole page.
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