Drug interactions
ethanol + metronidazole
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.
Overview
Concomitant use may trigger a disulfiram-like reaction (flushing, tachycardia, hypotension, nausea/vomiting, abdominal cramps). Avoid alcohol during therapy and for at least 72 hours after the last dose.
Mechanism of action
Proposed inhibition of aldehyde dehydrogenase by metronidazole → ↑ acetaldehyde with ethanol → disulfiram-like reaction.
Clinical management
Contraindicated: advise complete abstinence from ethanol-containing products during metronidazole therapy and for ≥3 days after completion; consider alternative therapy if abstinence is not feasible.
Drug reference
References
- Flagyl (metronidazole) Prescribing Information — FDA Label
- Metronidazole: Drug Information — UpToDate
- Metronidazole—Drug Interactions — Lexicomp
Frequently asked questions
Can I take ethanol with metronidazole?
The interaction is rated: Contraindicated. Concomitant use may trigger a disulfiram-like reaction (flushing, tachycardia, hypotension, nausea/vomiting, abdominal cramps). Avoid alcohol during therapy and for at least 72 hours after the last dose.
How serious is the interaction between ethanol and metronidazole?
The interaction is rated: Contraindicated. Evidence level: High.
How is the interaction between ethanol and metronidazole managed?
Contraindicated: advise complete abstinence from ethanol-containing products during metronidazole therapy and for ≥3 days after completion; consider alternative therapy if abstinence is not feasible.
Why do ethanol and metronidazole interact?
Proposed inhibition of aldehyde dehydrogenase by metronidazole → ↑ acetaldehyde with ethanol → disulfiram-like reaction.
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