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Sildenafil and alpha-blocker — GPhC CRA MCQ

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ModerateDrug InteractionsSildenafil and alpha-blockerGPhC CRA

A 63-year-old man taking doxazosin for urinary symptoms asks for sildenafil. He reports dizziness when standing since his doxazosin dose was increased. What is the most important interaction to flag?

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Correct answer: B — Sildenafil may add to postural hypotension with doxazosin

Both sildenafil and alpha-blockers can lower blood pressure. Existing postural dizziness increases concern about symptomatic hypotension. The pharmacist should assess suitability, timing, dose and need for prescriber advice. Neutropenia and absorption failure are not the main interaction concerns.

Reference: BNF