OBJECTIVE: To review the place in therapy of mirabegron, a new oral 
β3-adrenergic receptor agonist, for the treatment of overactive bladder (OAB).
DATA SOURCES: A literature search of MEDLINE and MEDLINE In-Process & Other 
Non-Indexed Citations Databases (1996-April 2013) was conducted using the key 
words mirabegron, receptor, adrenergic, beta-3; adrenergic beta-3 receptor; 
beta-3 receptor, and overactive bladder; urinary bladder; overactive. All 
published articles regarding mirabegron were included. References of selected 
articles, data from poster presentations, and abstract publications were 
additionally reviewed.
STUDY SELECTION AND DATA EXTRACTION: Available English-language data from 
reviews, abstracts, presentations, and clinical trials of mirabegron in humans 
were reviewed; relevant clinical data were selected and included.
DATA SYNTHESIS: Mirabegron is the newest option for treatment of OAB with 
symptoms of urge incontinence. As a β3-receptor agonist, it reduces bladder 
muscle contractions. In two 12-week, randomized, double-blind, 
placebo-controlled Phase 3 studies, mirabegron significantly reduced the number 
of incontinence episodes per 24 hours from baseline (-1.47, -1.63, and -1.13; p 
< 0.05; and -1.57, -1.46, and -1.17; p < 0.05; all values for mirabegron 50 mg, 
100 mg, and placebo). Micturitions per 24 hours were also reduced from baseline 
(-1.66, -1.75, and -1.05; p < 0.05; and -1.93, -1.77, and -1.34; p < 0.05; all 
values for mirabegron 50 mg, 100 mg, and placebo). A 12-month trial found 
mirabegron to have a safety and efficacy profile similar to that of tolterodine.
CONCLUSIONS: Treatment of OAB initially includes lifestyle and nonpharmacologic 
intervention; for patients with persistent symptoms despite these treatments, 
drug therapy represents a next-step approach for symptom control. Mirabegron 
alleviates symptoms of OAB while having a mechanism of action that provides an 
alternative for patients who are intolerant of or who have contraindications to 
anticholinergic agents. The place in therapy of mirabegron relative to 
anticholinergics in the treatment of urge incontinence has not yet been 
established.