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Warfarin and metronidazole — GPhC CRA MCQ

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ModerateCardiovascular TherapeuticsWarfarin and metronidazoleGPhC CRA

A patient stabilised on warfarin is prescribed metronidazole 400 mg three times daily for dental infection. What is the most important interaction to flag?

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Correct answer: A — Increased anticoagulant effect and bleeding risk

Metronidazole can increase the anticoagulant effect of warfarin and increase bleeding risk. This makes increased anticoagulant effect and bleeding risk the single best answer in this scenario. The other options would either miss the key safety issue, delay appropriate review, or fail to meet the relevant clinical or professional requirement.

Reference: BNF interactions