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DOAC monitoring — GPhC CRA MCQ

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HardCardiovascular TherapeuticsDOAC monitoringGPhC CRA

A patient stable on warfarin is prescribed metronidazole for a dental infection. What anticoagulation plan is required?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Contact the anticoagulation service for early INR-led dose review

Metronidazole can inhibit warfarin metabolism and raise INR and bleeding risk, sometimes substantially. The anticoagulation service should arrange earlier INR testing and adjust warfarin using results; timing separation does not prevent a metabolic interaction.

Reference: BNF: warfarin sodium: https://bnf.nice.org.uk/drugs/warfarin-sodium/