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Sildenafil and nitrates — GPhC CRA MCQ

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ModerateDrug InteractionsSildenafil and nitratesGPhC CRA

A 59-year-old man requests sildenafil for erectile dysfunction. His PMR shows glyceryl trinitrate spray issued last month for exertional chest pain, and he used it twice this week. His blood pressure today is 132/78mmHg. What is the most important interaction to flag?

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Correct answer: D — sildenafil with nitrates can cause severe hypotension

PDE5 inhibitors such as sildenafil are contraindicated with nitrates because the combination can cause profound hypotension. Recent GTN use makes supply unsafe without prescriber review. The patient also needs assessment of cardiovascular fitness for sexual activity. The interaction is pharmacodynamic rather than reduced absorption.

Reference: BNF