Pharmacology · single question
A long antibiotic prescription question: all options describe instructions. Which is the KEY instruction about metronidazole?
Show answer and explanation
Correct answer: B. Do not consume alcohol while taking metronidazole
B) Do NOT consume alcohol — CORRECT.
Metronidazole (Flagyl) has a well-known disulfiram-like reaction when combined with alcohol. It inhibits acetaldehyde dehydrogenase, causing accumulation of acetaldehyde → nausea, vomiting, flushing, tachycardia, hypotension. Patients must avoid ALL alcohol (including mouthwash with alcohol) during treatment and for 48–72 hours after finishing the course.
A) Dairy: No significant interaction with metronidazole.
C) Empty stomach: Can be taken with food to reduce GI upset — no strict requirement.
D) Warfarin: Metronidazole DOES interact with warfarin (increases bleeding risk) — this must be monitored.
Metronidazole (Flagyl) has a well-known disulfiram-like reaction when combined with alcohol. It inhibits acetaldehyde dehydrogenase, causing accumulation of acetaldehyde → nausea, vomiting, flushing, tachycardia, hypotension. Patients must avoid ALL alcohol (including mouthwash with alcohol) during treatment and for 48–72 hours after finishing the course.
A) Dairy: No significant interaction with metronidazole.
C) Empty stomach: Can be taken with food to reduce GI upset — no strict requirement.
D) Warfarin: Metronidazole DOES interact with warfarin (increases bleeding risk) — this must be monitored.