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Oral thrush and warfarin — GPhC CRA MCQ

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HardInfectionsOral thrush and warfarinGPhC CRA

A patient taking warfarin asks to buy miconazole oral gel for suspected oral thrush. Their INR has been unstable recently. What is the most important interaction to flag?

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Correct answer: E — Miconazole can greatly increase warfarin anticoagulant effect

Miconazole oral gel can significantly increase the anticoagulant effect of warfarin and cause serious bleeding. It should generally be avoided unless close INR monitoring and prescriber oversight are arranged. The pharmacist should refer for an alternative antifungal plan. The interaction is pharmacokinetic and clinically important even with topical oral gel.

Reference: BNF