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Benign prostatic hyperplasia with treated LUTS and coexisting erectile dysfunction — MSRA MCQ

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ModerateBPHBenign prostatic hyperplasia with treated LUTS and coexisting erectile dysfunctionMSRA

A 70-year-old man has taken tamsulosin MR 400 micrograms daily for 6 months for bothersome voiding LUTS due to benign prostatic enlargement. His LUTS are now well controlled. He reports persistent erectile dysfunction and wishes to try oral treatment. His blood pressure is 128/74 mmHg, with no postural symptoms. He can walk briskly for 30 minutes without chest pain or undue breathlessness. He takes amlodipine only, and does not take nitrates, nicorandil, riociguat or ritonavir. He has no recent myocardial infarction or stroke, severe hepatic impairment, visual loss due to non-arteritic anterior ischaemic optic neuropathy, or penile deformity. What is the most appropriate pharmacological plan?

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

Reveal the answer and explanation

Correct answer: A — Continue tamsulosin and start sildenafil 25 mg as required

Explanation lettering: D = shown as A · A = shown as B · B = shown as C · E = shown as D · C = shown as E

D is correct. He has a separate licensed indication for sildenafil—erectile dysfunction—and has no stated cardiovascular, nitrate-related or other major contraindication. He has also been stable on tamsulosin for 6 months without postural symptoms. However, alpha-blockers and sildenafil can both lower blood pressure. The sildenafil SmPC advises that patients are haemodynamically stable on alpha-blocker treatment before sildenafil is introduced and that a 25 mg starting dose should be considered to reduce the risk of symptomatic postural hypotension. A uses the usual sildenafil starting dose but does not account for concurrent alpha-blockade. B is attractive because hypotension is most likely within 4 hours of sildenafil dosing, but dose separation is not a substitute for the recommended cautious initial dose. C unnecessarily withdraws effective alpha-blockade; finasteride has a delayed effect and may itself worsen sexual function. E overstates the interaction: concomitant alpha-blocker use requires caution and dose adjustment, not avoidance where the patient is stable. NICE advises against PDE5 inhibitors solely to treat LUTS, but sildenafil here is being prescribed for coexisting erectile dysfunction.

Reference: Sildenafil 25 mg film-coated tablets - Summary of Product Characteristics (Last updated 17 June 2026) — https://www.medicines.org.uk/emc/product/11012/smpc NICE CG97: Lower urinary tract symptoms in men: management, drug treatment recommendation 1.4.11 (2015; last reviewed December 2024) — https://www.nice.org.uk/guidance/cg97/chapter/recommendations