Drug interactions
Erythromycin lactobionate + Metronidazole
Severity: Moderate
Erythromycin lactobionate 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
Both drugs have been associated with QT prolongation, and intravenous erythromycin carries particular proarrhythmic risk. Combined use may add to arrhythmia risk.
What this interaction means in plain words
Erythromycin lactobionate 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.
Erythromycin lactobionate belongs to Anti Bacterial; Metronidazole belongs to Anti Parasitic.
Why it happens
Additive QT interval prolongation; metronidazole CYP3A4 inhibition is weak at most.
What to do
Correct potassium and magnesium and monitor ECG during intravenous therapy, especially with other QT risk factors. Choose an alternative if QT prolongation develops.
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 Erythromycin lactobionate
- Cisapride + Erythromycin lactobionate Contraindicated
- Dihydroergotamine + Erythromycin lactobionate Contraindicated
- Dronedarone + Erythromycin lactobionate Contraindicated
- Eletriptan + Erythromycin lactobionate Contraindicated
- Ergotamine + Erythromycin lactobionate Contraindicated
- Erythromycin lactobionate + Flibanserin Contraindicated
Frequently asked questions
Can I take Erythromycin lactobionate with Metronidazole?
MediHelp rates the interaction as moderate. Erythromycin lactobionate 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. Both drugs have been associated with QT prolongation, and intravenous erythromycin carries particular proarrhythmic risk. Combined use may add to arrhythmia risk.
How serious is the interaction between Erythromycin lactobionate 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: Correct potassium and magnesium and monitor ECG during intravenous therapy, especially with other QT risk factors. Choose an alternative if QT prolongation develops.
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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