From the Guidelines
To avoid a disulfiram-like reaction while taking metronidazole, patients should completely avoid alcohol consumption during treatment and for at least 24 hours thereafter. This is based on the recommendation from the Centers for Disease Control and Prevention in 1993 1. Although this guideline is not the most recent, a more recent study in 2021 also advises patients to avoid alcohol for the therapeutic duration due to a disulfuram-like reaction 1. It is essential to note that the reaction occurs because metronidazole inhibits the enzyme aldehyde dehydrogenase, which is responsible for breaking down acetaldehyde, an intermediate product of alcohol metabolism. When alcohol is consumed while this enzyme is blocked, acetaldehyde accumulates in the bloodstream, causing unpleasant and potentially dangerous symptoms.
- These symptoms can include facial flushing, severe headache, nausea, vomiting, abdominal cramps, chest pain, rapid heartbeat, difficulty breathing, and low blood pressure.
- Patients should carefully read labels on over-the-counter medications and food products to ensure they don't contain alcohol while taking metronidazole.
- All forms of alcohol should be avoided, including beer, wine, liquor, and even alcohol-containing products like certain mouthwashes, cough syrups, cooking wines, and some food preparations.
From the FDA Drug Label
Alcoholic beverages should be avoided while taking metronidazole tablets and for at least one day afterward. Alcoholic beverages should not be consumed during metronidazole therapy and for at least one day afterward because abdominal cramps, nausea, vomiting, headaches, and flushing may occur If patients receiving metronidazole drink alcoholic beverages, they may experience abdominal distress, nausea, vomiting, flushing, or headache.
To avoid a disulfiram-like reaction, alcoholic beverages should be avoided while taking metronidazole and for at least one day afterward 2, 2. This is because consuming alcohol during metronidazole therapy can cause symptoms such as abdominal cramps, nausea, vomiting, headaches, and flushing 2, 2, 2.