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Benign prostatic enlargement with persistent storage LUTS/overactive bladder symptoms — MSRA MCQ

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HardBPHBenign prostatic enlargement with persistent storage LUTS/overactive bladder symptomsMSRA

A 79-year-old man is reviewed in general practice 8 weeks after starting tamsulosin MR 400 micrograms once daily for bothersome LUTS attributed to benign prostatic enlargement. His hesitancy and weak stream have resolved, and post-void residual volume is 35 mL. However, he still has severe urgency, frequency and urge urinary incontinence (IPSS storage subscore 11). Urine culture is negative and a frequency-volume chart excludes nocturnal polyuria. He has vascular cognitive impairment, chronic constipation requiring regular macrogol, and treated hypertension. His blood pressure today is 168/102 mmHg despite amlodipine and candesartan. eGFR is 64 mL/min/1.73 m². He has no narrow-angle glaucoma, urinary retention, heart failure or diabetes. He wishes to try further drug treatment. Which is the most appropriate pharmacological plan?

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Correct answer: A — Add vibegron 75 mg once daily to tamsulosin, with monitoring for urinary retention

This man has persistent storage LUTS/overactive bladder symptoms despite successful relief of voiding obstruction with tamsulosin. His low residual volume and resolved voiding symptoms make an additional bladder-directed treatment reasonable, but the choice must account for comorbidity. Solifenacin is initially attractive because NICE supports adding an anticholinergic when storage symptoms persist after alpha-blocker treatment. However, antimuscarinics can worsen constipation and have central anticholinergic effects; vascular cognitive impairment and established troublesome constipation make this option unsuitable. Mirabegron is an alternative beta-3 agonist when antimuscarinics are unsuitable, but it can increase blood pressure and its SmPC states that evidence is limited in stage 2 hypertension (systolic at least 160 mmHg or diastolic at least 100 mmHg). His current blood pressure is therefore an important discriminator. Vibegron is NICE-recommended for adult overactive bladder when antimuscarinics are unsuitable. Its SmPC does not show a clinically meaningful blood-pressure effect when co-administered with amlodipine, while acknowledging that urinary retention risk is increased in clinically significant bladder outlet obstruction. Continuing tamsulosin, the low residual volume and monitoring for retention make vibegron the best option here. Finasteride addresses long-term progression risk from prostatic enlargement rather than urgency-predominant symptoms. Desmopressin is for confirmed nocturnal polyuria, which has been excluded.

Reference: Lower urinary tract symptoms in men: management — Recommendations (Last reviewed 19 December 2024) — https://www.nice.org.uk/guidance/cg97/chapter/recommendations Vibegron for treating symptoms of overactive bladder syndrome — Recommendations (04 September 2024) — https://www.nice.org.uk/guidance/ta999/chapter/1-Recommendations?UNLID=486013771202591871532 Mirabegron Astellas 50 mg prolonged-release tablets — Summary of Product Characteristics (Updated 2025) — https://www.medicines.org.uk/emc/product/7540/smpc