Adding mirabegron after intravesical onabotulinumtoxinA injection improves therapeutic effects in patients with refractory overactive bladder.

To investigate whether adding an anticholinergic or beta-3 agonist can improve the therapeutic effect of intravesical onabotuliumtoxinA injection in patients with refractory overactive bladder (OAB).

Ninety OAB patients who received an intravesical 100-U onabotulinumtoxinA injection 1 month previously were consecutively invited into a prospective, randomized, open-label study. They were randomly adding on solifenacin 5 mg daily (QD) (30 patients), mirabegron 50 mg QD (31 patients), or no medication (29 patients, control). All enrolled patients completed a 3-day voiding diary, Overactive Bladder Symptom Score (OABSS) and Urgency Severity Scale (USS) questionnaires, Global Response Assessment (GRA) scale, and uroflowmetry at baseline (1 month after intravesical onabotulinumtoxinA injection) and 3-, 6-, 9-, and 12-month follow-up. The primary end point was the effective therapeutic outcome defined as no OAB wet during the 12-month period. The secondary end point included changes of GRA, OABSS, and the parameters of the voiding diary at 3 months.

The baseline data were comparable among the three groups. The percentage of OAB wet in the mirabegron-added-on group was significantly less than that in the solifenacin-added-on and onabotulinumtoxinA-only groups at four different time points (P = .02). At 3 months, the changes of GRA, OABSS, USS, urge urinary incontinence, frequency, nocturia episodes, and functional bladder capacity in the mirabegron-added-on group were significantly greater than those in the other groups. No serious adverse events were reported.

Adding mirabegron could increase the therapeutic effects, mainly on OAB symptoms and GRA scale, after intravesical onabotulinumtoxinA injection in refractory OAB patients.

Lower urinary tract symptoms. 2021 May 06 [Epub ahead of print]

Chung-Cheng Wang, Cheng-Ling Lee, Yi-Ting Hwang, Hann-Chorng Kuo

Department of Urology, En Chu Kong Hospital, College of Medicine, National Taiwan University, New Taipei City, Taiwan., Department of Urology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, and Buddhist Tzu Chi University, Hualien, Taiwan., Department of Statistics, National Taipei University, New Taipei City, Taiwan.