What reaction occurs if metronidazole is taken with alcohol?

When metronidazole is taken with alcohol, a disulfiram-like reaction can occur. This reaction is characterized by a combination of flushing, nausea, vomiting, headache, and abdominal cramps. Disulfiram (commonly known as Antabuse) is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol, leading to unpleasant symptoms if alcohol is consumed. Metronidazole, while not an alcohol deterrent like disulfiram, can produce similar symptoms due to its interaction with the metabolic processing of alcohol.

The mechanism behind this lies in the way metronidazole affects the metabolism of alcohol, inhibiting the enzyme aldehyde dehydrogenase, which is responsible for breaking down acetaldehyde, a by-product of alcohol metabolism. When alcohol is consumed, acetaldehyde levels can rise significantly, leading to the adverse symptoms mentioned above. This interaction highlights the importance of advising patients to avoid alcohol while taking metronidazole to prevent these uncomfortable and potentially dangerous reactions.