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Overactive bladder syndrome — MSRA MCQ

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HardUrologyOveractive bladder syndromeMSRA

A 79-year-old woman has urgency urinary incontinence, frequency and nocturia despite 8 weeks of bladder training, caffeine reduction and treatment of genitourinary syndrome of menopause with vaginal oestrogen. A 3-day bladder diary supports overactive bladder. Urine culture is negative and post-void residual volume is 45 mL. She previously stopped immediate-release oxybutynin because of severe dry mouth, constipation and an episode of acute confusion. She has mild vascular cognitive impairment and takes donepezil. She also takes flecainide for paroxysmal atrial fibrillation. Her blood pressure, repeated after 10 minutes, is 182/112 mmHg; she is asymptomatic. Which is the most appropriate pharmacological treatment for her overactive bladder symptoms?

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

Reveal the answer and explanation

Correct answer: D — Start vibegron 75 mg once daily

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

Vibegron is the best option. Her symptoms and bladder diary support overactive bladder, and infection and significant incomplete emptying have been excluded. Antimuscarinics are unsuitable: she had unacceptable anticholinergic adverse effects with oxybutynin, has vascular cognitive impairment, takes donepezil, and already has a clinically important vulnerability to anticholinergic cognitive effects. NICE recommends vibegron as an option when antimuscarinics are unsuitable, ineffective or not tolerated. Mirabegron is an attractive alternative beta-3 agonist, but is contraindicated in severe uncontrolled hypertension, defined as systolic blood pressure of at least 180 mmHg and/or diastolic pressure of at least 110 mmHg. Her confirmed blood pressure meets this threshold. Its SmPC also advises caution with narrow-therapeutic-index CYP2D6 substrates, including class 1C antiarrhythmics such as flecainide. Her hypertension also requires prompt assessment and management. A is inappropriate because immediate-release oxybutynin is specifically unsuitable in an older person at risk of acute physical or mental deterioration and previously caused harm. B remains an antimuscarinic and adds to cognitive and anticholinergic risk. E may reduce nocturia but is not appropriate for predominant overactive bladder in a woman over 65 years with hypertension and cardiovascular disease.

Reference: NICE NG123: Urinary incontinence and pelvic organ prolapse in women: management — Medicines for overactive bladder (2019; links updated March 2025) — https://www.nice.org.uk/guidance/ng123/chapter/recommendations NICE TA999: Vibegron for treating symptoms of overactive bladder syndrome — Recommendations (4 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