Adding antimuscarinic or mirabegron Increases the therapeutic effect in overactive bladder patients treated with 100 U onabotulinumtoxinA

Wang C1, Lee Y2, Jiang Y2, Kuo H2

Research Type


Abstract Category


Abstract 524
Open Discussion ePosters
Scientific Open Discussion ePoster Session 28
Friday 31st August 2018
13:15 - 13:20 (ePoster Station 3)
Exhibition Hall
Overactive Bladder Pharmacology Clinical Trial
1. Department of Urology, En Chu Kong Hospital, New Taipei City, Taiwan, 2. Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan

Chung-Cheng Wang




Hypothesis / aims of study
To test the hypothesis that combining antimuscarinic or mirabegron can increase the therapeutic effect after overactive bladder (OAB) patients receiving intradetrusor onabotuliumtoxinA injection.
Study design, materials and methods
The Institutional Review Board and Ethics Committee of the hospital approved this study. Thirty-three OAB patients, who received intravesical 100 U onabotulinumtoxinA injection one month ago, were consecutively invited to a prospective, randomized, open-label study. They were randomly treated with solifenacin 5 mg QD in 11 patients (group 1), mirabegron 50 mg QD in 11 patients (group 2) and without medication in 11 patients (group 3). All enrolled patients were asked to complete 3-day voiding diary, the Overactive Bladder Symptom Score (OABSS), Urgency Severity Scale (USS) questionnaires, and uroflowmetry at baseline and 3-month. Videourodynamic study was performed before intravesical onabotulinumtoxinA injection. The primary endpoint was changes of Global Response Assessment (GRA) at 3-month. The secondary endpoint included changes of OABSS, USS and the parameters of voiding diary.
The mean patients’ age was 73.9±9.8, 66.9±13.4 and 71.2±10.2 (p=0.35) in group 1,2 and 3 respectively. The baseline data were comparable in three groups. Compared with baseline, OABSS in group 1 and 2 was significantly decreased at 3-month but not in group 3. At 3-month, GRA in group 1 and 2 was significantly higher than group 3 (1.3 ± 0.7, 1.8 ± 1.0 versus 0.1 ± 1.6, p=0.04) (Table 1). The differences of OABSS, functional bladder capacity and nocturia episodes between baseline and 3-month in group 1 and 2 were also significantly different from those in group 3.
Interpretation of results
AUA/SUFA OAB guideline suggests that specialists may offer intradetrusor onabotulinumtoxinA (100 U) as third-line treatment in patients refractory to first- and second-line OAB treatments. This recommendation implies that no pharmacological therapy is needed after patients received intradetrusor onabotulinumtoxinA injection. However, our study showed patients resuming antimuscarinics or beta-3 agonist after intravesical onabotulinumtoxinA injection had better therapeutic effects than those without any medication. Due to the different mechanisms involving OAB pathophysiology, combined the second-line and third-line treatment might be another choice for refractory OAB patients.
Concluding message
Adding antimuscarinic or beta-3 agonist can increase the therapeutic effect in patients after receiving intradetrusor onabotulinumtoxinA injection.
Figure 1
Funding None Clinical Trial Yes Public Registry No RCT Yes Subjects Human Ethics Committee Research Ethics Committee, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation Helsinki Yes Informed Consent Yes