Natty asked
If I only took one Flagyl (metronidazole) tablet, will I be okay to drink alcohol the next day?
Answer
Due to the potential for a "disulfiram-like reaction", Flagyl (metronidazole) should not be consumed with alcohol (which includes beer, wine and liquor) during therapy and for three days after your last dose. Therefore, it is not recommended to consume alcohol the day after your last dose of metronidazole. You should wait three days to be safe.
The prescribing information for Flagyl (metronidazole) specifically mentions this three day window:
Use of oral metronidazole is associated with a disulfiram-like reaction to alcohol, including abdominal cramps, nausea, vomiting, headaches, and flushing. Discontinue consumption of alcohol and products containing propylene glycol during and for at least three days after therapy with metronidazole.
We have written a few articles related to this subject:
What Is The Reaction Between Metronidazole And Alcohol?
Flagyl (metronidazole) and a number of other drugs/substances (e.g. propylene glycol) can inhibit aldehyde dehydrogenase, which is necessary for metabolism of alcohol in our body, potentially causing it to accumulate to toxic levels. This has the potential to cause side effects that manifest as alcohol toxicity:
- Nausea
- Vomiting
- Diarrhea
- Flushing
- Dizziness
- Altered consciousness
The reaction between metronidazole and alcohol is classified as "disulfiram-like" based on the effects that the drug disulfiram has with alcohol. Although not used as much currently as it has been in the past, disulfiram is a prescription medication used treat alcohol dependence as it inhibits alcohol metabolism, which can cause many of the effects listed above. Basically, you take it as a deterrent to alcohol use. In those taking disulfiram, negative reactions can occur after consuming as little as 15 mL (one tablespoon) of ethanol.
There is some controversy in regard to just how risky it is to consume alcohol with metronidazole (as discussed in our linked article), but to be safe, you should abstain from alcohol for more than one day after your last dose. Three days should be the minimum.
In terms of only taking one dose of Flagyl, there isn't much data to indicate whether or not a single dose will cause as many (or any) issues with alcohol. Due to the lack of data, the same recommendation applies...Wait three days before consuming alcohol.
