Summary: Metronidazole has long been accused of making people sick if they drink alcohol with it. Recent studies have not been able to prove that this reaction exists. However, I have personally seen this reaction. It’s generally recommended you wait at least 48 hours from your last metronidazole dose before you drink alcohol.
Dear Curtis: I’m taking Metronidazole (Flagyl) for an infection. How long do I have to wait before I can drink any alcohol?
If we are talking about the oral tablets (metronidazole also comes in a vaginal gel) then it’s recommended that you wait at least 48 hours after your last dose of metronidazole before you drink any alcohol.
However, like many things in medicine, this ‘no alcohol with Flagyl rule has recently come under question.
Disulfiram Reaction Questioned
When I was in school we were taught that metronidazole gave users a disulfiram reaction with alcohol. This is named after the drug disulfiram (Antabuse). Antabuse is a drug that can be given to alcoholics to prevent them from drinking.
Essentially it get’s them sicker than a dog by not allowing the body to digest and break down alcohol – leading to nausea, vomiting, increased heart rate and all the signs and symptoms of too much booze and a raging hangover.
But one survey and one study recently challenged this “well-known fact” and showed that it may not be a fact at all and, in the second study, actually went so far as trying to replicate the supposed effects by having volunteers drink alcohol while they were taking metronidazole.(1,2)
While the study only involved 12 peopled, they were not able to prove that metronidazole has any subjective or objective effects on the participants. However, they did go onto say that enough individual case studies exist to suggest that there might be a subset of folks who are more likely to get a disulfiram-like reaction to alcohol.
Personally, I have seen this reaction to alcohol. So I always caution folks that it’s better to be safe than sorry.
- Williams CS, Woodcock KR (2000). “Do ethanol and metronidazole interact to produce a disulfiram-like reaction?”. The Annals of Pharmacotherapy 34 (2): 255–7.
- Visapää JP, Tillonen JS, Kaihovaara PS, Salaspuro MP (2002). “Lack of disulfiram-like reaction with metronidazole and ethanol”. The Annals of Pharmacotherapy 36 (6): 971–4