What is the alcohol interaction associated with metronidazole?

• A. Disulfiram-like reaction; avoid alcohol during therapy and for 24–72 hours after.
• B. No interaction; safe with alcohol.
• C. Alcohol improves effectiveness.
• D. Causes sedation when combined with alcohol.

Answer: (A)

Metronidazole can trigger a disulfiram-like reaction when alcohol is consumed. The drug interferes with alcohol metabolism, leading to a buildup of acetaldehyde. This causes unpleasant symptoms such as flushing, headache, palpitations, nausea, vomiting, sweating, and sometimes dizziness or low blood pressure. Because of this, patients should avoid alcoholic beverages and any products containing alcohol during the entire course of metronidazole therapy and for about 24 to 72 hours after the last dose to prevent these reactions. This is why the described interaction is correct. Alcohol does not enhance metronidazole’s effectiveness, and the reaction is not primarily a sedative interaction.