Drug interactions
Disopyramide + Metronidazole
Severity: Moderate
Disopyramide and Metronidazole: 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
Disopyramide is partly cleared by CYP3A4 and has a narrow therapeutic index with risks of QT prolongation and anticholinergic toxicity. Metronidazole may slightly increase its levels, and metronidazole itself has been associated with rare QT prolongation. The combined effect is generally small but relevant in patients with other arrhythmia risks.
What this interaction means in plain words
Disopyramide and Metronidazole 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.
Disopyramide belongs to Cardiovascular; Metronidazole belongs to Anti Parasitic.
Why it happens
Possible weak CYP3A4 inhibition by metronidazole plus additive QT-prolonging potential.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes in patients with additional risk factors; consider an alternative antibiotic if QTc lengthens.
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 Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Other interactions of Disopyramide
- Amisulpride + Disopyramide Contraindicated
- Desipramine + Disopyramide Contraindicated
- Disopyramide + Dronedarone Contraindicated
- Disopyramide + Itraconazole Contraindicated
- Disopyramide + Ketoconazole Contraindicated
- Disopyramide + Maprotiline Contraindicated
Frequently asked questions
Can I take Disopyramide with Metronidazole?
MediHelp rates the interaction as moderate. Disopyramide and Metronidazole 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. Disopyramide is partly cleared by CYP3A4 and has a narrow therapeutic index with risks of QT prolongation and anticholinergic toxicity. Metronidazole may slightly increase its levels, and metronidazole itself has been associated with rare QT prolongation. The combined effect is generally small but relevant in patients with other arrhythmia risks.
How serious is the interaction between Disopyramide and Metronidazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc and electrolytes in patients with additional risk factors; consider an alternative antibiotic if QTc lengthens.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Pimozide, Amiodarone. The full list is on the Metronidazole page.
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