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Nitrates and PDE5 inhibitors — GPhC CRA MCQ

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HardCardiovascular TherapeuticsNitrates and PDE5 inhibitorsGPhC CRA

A 66-year-old man uses isosorbide mononitrate modified-release 60mg daily for angina. He asks to buy sildenafil after seeing an online advert and says his angina has been stable. What is the most important interaction to flag?

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Correct answer: C — Sildenafil with nitrates may cause severe hypotension

Phosphodiesterase type 5 inhibitors can potentiate the vasodilator effect of nitrates. The combination can cause marked hypotension and is contraindicated. Stable angina does not make the combination safe. The patient should be advised to discuss erectile dysfunction management with a clinician.

Reference: BNF