skip to main content

Overactive bladder in an older woman with cognitive vulnerability and severe renal impairment — MSRA MCQ

Instant feedback + full explanation. One question, done properly.

HardLUTSOveractive bladder in an older woman with cognitive vulnerability and severe renal impairmentMSRA

A 78-year-old woman has 9 months of urinary urgency, frequency and urge urinary incontinence. A 3-day bladder diary shows 12 small-volume voids daily, with urgency preceding leakage; nocturnal urine volume is 23% of her 24-hour output. Urine culture is negative and post-void residual volume is 30 mL. She has completed bladder training and reduced caffeine intake without adequate benefit. She has vascular dementia and takes amitriptyline 10 mg at night for neuropathic pain. Solifenacin 5 mg once daily was stopped after 10 days because her daughter observed marked new confusion and visual misperceptions, which resolved after withdrawal. Her geriatrician has advised avoiding further anticholinergic exposure. Blood pressure is 166/96 mmHg on repeated measurement. eGFR is 24 mL/min/1.73 m² and liver function tests are normal. What is the most appropriate next pharmacological treatment for her urinary symptoms?

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

Reveal the answer and explanation

Correct answer: C — Prescribe mirabegron 25 mg once daily with blood-pressure monitoring

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

This is overactive bladder: urgency-associated leakage, frequent small-volume voids, negative culture and a low residual volume make infection, retention and nocturnal polyuria unlikely. Conservative treatment has been insufficient. Anticholinergic treatment is clinically unsuitable because she has established dementia, substantial pre-existing anticholinergic exposure, and a clear reversible neurocognitive adverse effect after solifenacin. NICE advises taking account of cognitive impairment and total anticholinergic burden, and permits a beta-3 agonist when anticholinergics are unsuitable. Mirabegron is therefore appropriate. Her eGFR of 24 mL/min/1.73 m² constitutes severe renal impairment, for which the recommended daily dose is 25 mg rather than 50 mg. Her blood pressure of 166/96 mmHg requires monitoring and optimisation, but is below the SmPC contraindication threshold for severe uncontrolled hypertension (180 mmHg systolic and/or 110 mmHg diastolic). A and B would add further anticholinergic exposure despite prior anticholinergic delirium risk. C is inappropriate because her diary does not show nocturnal polyuria; additionally, desmopressin should be avoided in women over 65 with hypertension. D uses an excessive mirabegron dose for her renal function.

Reference: Urinary incontinence and pelvic organ prolapse in women: management — Recommendations (2019) — https://www.nice.org.uk/guidance/ng123/chapter/recommendations Mirabegron Astellas 50 mg prolonged-release tablets — Summary of Product Characteristics (2026) — https://www.medicines.org.uk/emc/product/7540/smpc