Mirabegron for treating symptoms of overactive bladder

Mirabegron (Betmiga, Astellas Pharma) has a marketing authorisation in the UK for the 'symptomatic treatment of urgency, increased micturition frequency and/or urgency incontinence as may occur in patients with overactive bladder (OAB)'. It is a beta-3-adrenoceptor agonist, which activates beta-3-adrenoceptors causing the bladder to relax, which helps it to fill and also to store urine. It is administered orally. Mirabegron will be available as 25 mg and 50 mg tablets, with the recommended dose being 50 mg daily, and 25 mg if there is renal or hepatic impairment.

The summary of product characteristics lists the following adverse reactions for mirabegron: urinary tract infection, tachycardia, vaginal infection, cystitis, palpitation, atrial fibrillation, dyspepsia, gastritis, urticaria, rash, rash macular, rash papular, pruritus, joint swelling, vulvovaginal pruritis, increased blood pressure, increased gamma-glutamyl transpeptidase, increased aspartate aminotransferase, increased alanine aminotransferase, eyelid oedema, lip oedema, leukocytoclastic vasculitis and purpura (rash). For full details of adverse reactions and contraindications, see the summary of product characteristics.

The list price indicated in the manufacturer's submission is £0.97 (excluding VAT) per 50 mg or 25 mg tablet, or an average cost of £27.06 per 28 days (assuming 1 tablet per day). Costs may vary in different settings because of negotiated procurement discounts.