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Nitrate contraindication after PDE5 inhibitor — DipIMC MCQ

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HardPre-hospital PharmacologyNitrate contraindication after PDE5 inhibitorDipIMC

A 75-year-old man with acute pulmonary oedema is severely breathless and hypertensive. He has taken sildenafil earlier in the evening. What is the most appropriate immediate action?

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

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Correct answer: B — Avoid nitrates and use alternative supportive measures with urgent transfer

Nitrates can cause profound hypotension after recent phosphodiesterase-5 inhibitor use, so they should be avoided despite pulmonary oedema. Supportive measures such as upright positioning, oxygen, CPAP where available and urgent transfer remain important. Morphine to suppress respiratory drive is unsafe. The pearl is that medication history can change standard emergency drug choices.

Reference: JRCALC Guidelines 2025; NICE Acute Heart Failure CG187