PURPOSE: We determined the safety and efficacy of each of 2 doses of botulinum toxin type A (BTX-A) (200 or 300 U BOTOX) injected into the detrusor for urinary incontinence caused by neurogenic detrusor overactivity of predominantly spinal cord origin.
MATERIALS AND METHODS: A total of 59 patients with urinary incontinence caused by neurogenic detrusor overactivity (due to spinal cord injury in 53 and multiple sclerosis in 6) requiring clean intermittent self-catheterization were randomized to receive a single dose into the detrusor of BTX-A (200 U or 300 U) or placebo. Changes in daily frequency of urinary incontinence episodes were monitored via a patient bladder diary during 24 weeks. Key urodynamic assessments (maximum cystometric capacity, reflex detrusor volume and maximum detrusor pressure during bladder contraction) were used to provide objective measures of the treatment effect on bladder function. The impact of treatment on quality of life was assessed using the Incontinence Quality of Life questionnaire.
RESULTS: There were significant posttreatment decreases in incontinence episodes from baseline in the 2 BTX-A groups (p </=0.05) but not in the placebo group. In addition, more patients who received BTX-A reported no incontinence episodes during at least 1 posttreatment evaluation period. Positive treatment effects were also reflected by significant improvements in bladder function in the BTX-A groups, as assessed by urodynamics and in patient quality of life. Benefits were observed from the first evaluation at week 2 to the end of the 24-week study. No safety concerns were raised.
CONCLUSIONS: Intramuscular injections of BTX-A into the detrusor can provide rapid, well tolerated, clinically significant decreases in the signs and symptoms of urinary incontinence caused by neurogenic detrusor overactivity during a 24-week study period.