skip to main content

Warfarin and miconazole oral gel — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

ModerateDrug InteractionsWarfarin and miconazole oral gelGPhC CRA

A patient taking warfarin asks to buy miconazole oral gel for suspected oral thrush. His INR was stable last week. He has no bleeding symptoms today. What is the most important interaction to flag?

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

Reveal the answer and explanation

Correct answer: B — Miconazole can increase warfarin effect and bleeding risk

Miconazole, including oral gel, can significantly increase the anticoagulant effect of warfarin and raise bleeding risk. The pharmacist should not treat this as a simple OTC sale without assessing and seeking a safer option or prescriber advice. A stable INR last week does not exclude interaction risk after starting miconazole. The key concern is increased anticoagulation rather than loss of warfarin efficacy.

Reference: BNF; MHRA Drug Safety Update