Efficacy of Botulinum Toxin A Injection for Neurogenic Detrusor Overactivity and Urinary Incontinence: A Randomized, Double-Blind Trial

Purpose: We determined the efficacy of onabotulinumtoxinA for neurogenic detrusor overactivity secondary to spinal cord injury or multiple sclerosis. Materials and Methods: In a prospective, double-blind, multicenter study 57 patients 18 to 75 years old with neurogenic detrusor overactivity secondary to spinal cord injury or multiple sclerosis and urinary incontinence (defined as 1 or more occurrences daily) despite current antimuscarinic treatment were randomized to onabotulinumtoxinA 300 U (28) or placebo (29) via cystoscopic injection at 30 intradetrusor sites, sparing the trigone. Patients were offered open label onabotulinumtoxinA 300 U at week 36 and followed a further 6 months while 24 each in the treatment and placebo groups received open label therapy. The primary efficacy parameter was daily urinary incontinence frequency on 3-day voiding diary at week 6. Secondary parameters were changes in the International Consultation on Incontinence Questionnaire and the urinary incontinence quality of life scale at week 6. Diary and quality of life evaluations were also done after open label treatment. Results: The mean daily frequency of urinary incontinence episodes was significantly lower for onabotulinumtoxinA than for placebo at week 6 (1.31 vs 4.76, p <0.0001), and for weeks 24 and 36. Improved urodynamic and quality of life parameters for treatment vs placebo were evident at week 6 and persisted to weeks 24 to 36. The most common adverse event in each group was urinary tract infection. Conclusions: In adults with antimuscarinic refractory neurogenic detrusor overactivity and multiple sclerosis onabotulinumtoxinA is well tolerated and provides clinically beneficial improvement for up to 9 months.