Adding a beta-3 agonist to treatment may increase therapeutic effect and duration in patients with refractory overactive bladder (OAB) receiving intravesical onabotulinum toxin-A injections, according to a poster presentation at the European Association of Urology 2020 virtual congress.

In a prospective open-label trial, investigators randomly assigned 84 patients who received an intradetrusor onabotulinum toxin-A injection (100 U) in the prior month to add-on solifenacin (5 mg daily), mirabegron (50 mg daily), or no medication.

At 3 months, the mirabegron group reported a significantly higher improvement in the Global Response Assessment than the no-medication group: 1.9 vs 0.6, Chung Cheng Wang, MD, of Chu Kong Hospital in New Taipei City, Taiwan, and colleagues reported. In addition, episodes of urgency and frequency assessed by the Overactive Bladder Symptom Score (OABSS) declined significantly in both the solifenacin and mirabegron groups.

Continue Reading

Overall, the mirabegron group reported significantly more improvement in OABSS, frequency, and nocturia from baseline to 3 months than the other groups. Patients in the mirabegron group also had the longest duration of successful treatment over 12 months.

The combination of oral mirabegron and intravesical BoNT-A may provide synergic effects in OAB because of their different mechanisms, according to Dr Wang’s team.


Wang CC, Lee CL, Kuo HC. Can combination of OAB medication and intravesical botulinum toxin A prolong the therapeutic duration and effect in patients with overactive bladder syndrome? Eur Urol Open Sci 19(2):e805. Presented at: EAU20 Virtual Congress; July 17 to 19, 2020. Poster 518.