Drinking alcohol while taking metronidazole is strongly advised against. Metronidazole, commonly known by the brand name Flagyl, is a widely prescribed antibiotic and antiparasitic medication used to treat various infections, including bacterial vaginosis, skin infections, and pelvic inflammatory disease. The interaction between metronidazole and alcohol is well-documented, and understanding the potential risks is important for anyone prescribed this medication.
Understanding the Interaction
The reason alcohol and metronidazole should not be combined is due to a “disulfiram-like reaction.” The body breaks down alcohol in a two-step process. First, an enzyme converts alcohol into acetaldehyde, a toxic compound. Another enzyme, aldehyde dehydrogenase, quickly breaks down acetaldehyde into acetate.
Metronidazole interferes with the body’s ability to process alcohol by affecting this second enzyme, aldehyde dehydrogenase. This interference leads to a rapid buildup of acetaldehyde in the bloodstream. The accumulation of this toxic compound causes the unpleasant and potentially severe symptoms associated with combining metronidazole and alcohol. While some research suggests the exact mechanism, particularly regarding the inhibition of hepatic aldehyde dehydrogenase, is not fully established or may involve other factors like gut flora changes, healthcare professionals consistently advise caution due to the risk of this reaction.
Potential Effects of Combining Alcohol
Consuming alcohol while taking metronidazole can trigger a range of symptoms, collectively known as a disulfiram-like reaction. Common reactions include nausea, vomiting, abdominal pain or cramps, and headaches. Individuals may also experience flushing of the skin, dizziness, and a rapid or pounding heartbeat (palpitations).
These reactions vary in severity, but can be unpleasant and debilitating. In severe cases, symptoms can include severe chest pain, a sudden drop in blood pressure, or difficulty breathing, which warrant immediate medical attention. One reported death has been associated with this interaction.
Guidelines for Alcohol Avoidance
It is recommended to avoid alcohol while taking metronidazole and for a specified period after the last dose. Healthcare professionals advise abstaining from alcohol for at least 24 to 72 hours after completing the course of metronidazole. This waiting period allows the medication to be sufficiently cleared from the body, as metronidazole can remain in the system for up to 50 hours.
Beyond alcoholic drinks, be aware of hidden sources of alcohol in various products. Some liquid medications, such as cough syrups, cold remedies, and certain elixirs, can contain alcohol. Mouthwashes and even some food products, like certain extracts (e.g., vanilla extract), sauces, and baked goods, may also contain alcohol. Checking labels for these hidden sources is important for complete avoidance during and after metronidazole treatment.
Steps After Accidental Alcohol Consumption
If alcohol is accidentally consumed while taking metronidazole, stop drinking immediately. Individuals may experience symptoms ranging from mild to serious. If symptoms are mild, such as stomach cramps, nausea, or flushing, they should resolve on their own.
However, if severe symptoms occur, including severe vomiting, chest pain, extreme dizziness, or difficulty breathing, seek emergency medical attention promptly. Even if symptoms are mild, contacting a healthcare provider for advice is recommended, especially if there are concerns or if the individual has underlying health conditions. Resting in a quiet place and drinking plenty of water can help manage mild discomfort while monitoring symptoms.