Which precaution is advised when a patient is treated with metronidazole (Flagyl) for an ulcerative colitis flare?

Which precaution is advised when a patient is treated with metronidazole (Flagyl) for an ulcerative colitis flare?

• A. Avoid alcohol during therapy
• B. Avoid dairy products
• C. Avoid iron supplements
• D. Take with grapefruit juice

Answer: (A)

Metronidazole can cause a disulfiram-like reaction when alcohol is consumed. This reaction happens because alcohol metabolism leads to acetaldehyde buildup, which can cause flushing, nausea, vomiting, tachycardia, dizziness, and sometimes low blood pressure. To prevent these unpleasant and potentially risky symptoms, patients should avoid all alcoholic beverages during therapy and for about 24 to 48 hours after finishing the course (including hidden alcohol in mouthwash, cough syrups, etc.). The other potential precursors listed—dairy products, iron supplements, or grapefruit juice—do not have a meaningful interaction with metronidazole, so they do not require avoidance for this medication.

Metronidazole can cause a disulfiram-like reaction when alcohol is consumed. This reaction happens because alcohol metabolism leads to acetaldehyde buildup, which can cause flushing, nausea, vomiting, tachycardia, dizziness, and sometimes low blood pressure. To prevent these unpleasant and potentially risky symptoms, patients should avoid all alcoholic beverages during therapy and for about 24 to 48 hours after finishing the course (including hidden alcohol in mouthwash, cough syrups, etc.). The other potential precursors listed—dairy products, iron supplements, or grapefruit juice—do not have a meaningful interaction with metronidazole, so they do not require avoidance for this medication.