FDA Approves Drug for Overactive Bladder

The FDA has approved the drug mirabegron (Myrbetriq) to treat overactive bladder, the agency announced on Thursday. The once-daily, extended-release tablet relaxes the bladder muscle during filling, thereby increasing the bladder's storage capacity.

In three clinical trials, more than 4000 patients with overactive bladder were randomized to mirabegron or placebo for 12 weeks. The 25- and 50-mg doses reduced the number of times a patient urinated and had wetting accidents over 24 hours. The 50-mg dose was also associated with more urine expelled.

Side effects included increased blood pressure, nasopharyngitis, urinary tract infection, constipation, fatigue, tachycardia, and abdominal pain. Patients with severe uncontrolled hypertension, end-stage renal disease, or severe liver impairment should not take the drug.