Short-term Efficacy of Botulinum Toxin A for Refractory Overactive Bladder in Female Patients.

Background/aim: This study aimed to assess the effectiveness and safety of 100 U onabotulinumtoxinA (also known as botulinum toxin type A) for overactive bladder (OAB) and urgency urinary incontinence (UUI) in Japanese women.

Patients and methods: This prospective, nonrandomized study was conducted as a single-center clinical trial in Japan and targeted patients with OAB that did not respond adequately to standard treatments, including anticholinergics and β3-adrenergic receptor agonists. A total of 26 patients received a single intradetrusor injection of onabotulinumtoxinA. The primary endpoint was the change in the number of daily UUI episodes between baseline and week 12. The secondary endpoints were improvements in other OAB symptoms and health-related quality of life (HRQoL). Adverse events were monitored.

Results: Patients who received onabotulinumtoxinA experienced a significant reduction in the mean number of daily UUI episodes between baseline and week 12 (-3.49; p<0.001). Significant improvements in all secondary endpoints except the personal relationships domain of King's Health Questionnaire were observed. Adverse events, such as urinary tract infection, cystitis, dysuria, and increased postvoid residual urine volume, occurred more frequently with onabotulinumtoxinA. However, the severity of most adverse events was mild or moderate.

Conclusion: OnabotulinumtoxinA administered at a dose of 100 U was well-tolerated and resulted in significant and clinically meaningful improvements in the OAB symptoms and HRQoL of patients whose OAB could not be adequately managed with other treatments.