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Acute urinary retention precipitated by pseudoephedrine in benign prostatic enlargement — MSRA MCQ

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HardBPHAcute urinary retention precipitated by pseudoephedrine in benign prostatic enlargementMSRA

A 70-year-old man with previously untreated bothersome voiding LUTS due to benign prostatic enlargement develops complete inability to pass urine over 12 hours, with increasing suprapubic pain. For the past 4 days he has taken an over-the-counter cold remedy containing pseudoephedrine. He is afebrile and haemodynamically stable. There is a tender palpable bladder; bladder scan shows 940 mL. Urine dipstick is negative for leucocytes and nitrites. He has no back pain, saddle sensory change, leg weakness or constipation. Creatinine is 84 micromol/L and eGFR is 79 mL/min/1.73 m². He has no history of postural hypotension, cataract surgery or severe hepatic impairment. Which immediate management plan is most appropriate?

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Correct answer: A — Insert a urethral catheter immediately, stop pseudoephedrine, start an alpha blocker before catheter removal and arrange specialist assessment

This is acute urinary retention: complete inability to void, painful palpable bladder and a residual volume of 940 mL. The immediate priority is bladder decompression by urethral catheterisation; normal renal function does not justify delaying this. Pseudoephedrine is a sympathomimetic and can precipitate or worsen retention in men with prostatic enlargement, so it should be withdrawn. NICE recommends offering an alpha blocker for acute urinary retention before catheter removal, improving the prospect of a successful trial without catheter. Retention also warrants specialist assessment. A is unsafe because stopping the precipitant and commencing tamsulosin do not decompress an acutely distended bladder. B gets catheterisation and withdrawal of pseudoephedrine right, but incorrectly delays alpha blockade until after a failed trial without catheter. C applies investigations associated with chronic retention but wrongly postpones urgent drainage. E includes decompression, but continuing the likely precipitant is inappropriate and finasteride has no useful immediate effect in acute retention; it does not replace an alpha blocker before catheter removal.

Reference: NICE: Lower urinary tract symptoms in men: management — Recommendations (2010; current page checked 15 August 2026) — https://www.nice.org.uk/guidance/cg97/chapter/recommendations Sudafed Decongestant Tablets — Summary of Product Characteristics (2025) — https://www.medicines.org.uk/emc/product/6199/smpc