Outcome of a randomized, double-blind, placebo controlled trial of botulinum A toxin for refractory overactive...

We determined the effectiveness of cystoscopic administration of botulinum-A toxin compared to placebo for the treatment of urinary incontinence in subjects with idiopathic overactive bladder.

Subjects were recruited from the Division of Urogynecology at the University of Rochester. Inclusion criteria were overactive bladder refractory to anticholinergic medications, multiple daily incontinence episodes and a 24-hour pad weight of 100 gm or greater. Subjects with low leak point pressures, increased post-void residual volume or neurological etiologies were excluded from study. Subjects were randomized to placebo or to 1 of 2 doses of botulinum-A toxin. The detrusor was injected at 8 to 10 sites above the trigone. Evaluations were performed at baseline, and at 3 and 6 weeks after injection, and included bladder diaries, pad weights, quality of life questionnaires and urodynamic studies.

A total of 22 subjects participated in stage 1 of this 2-stage study. We report on the outcomes of stage 1 of this study. Because stage 2 is still ongoing and investigators remain blind to the doses of botulinum-A toxin, the 2 botulinum-A toxin groups were combined for this report. There were no differences in mean baseline measurements between the 2 groups. Statistically significant improvements in daily incontinence episodes, pads changed per day and quality of life questionnaires were seen in the botulinum-A toxin group with no changes in the placebo group. No change in nocturia, daily voiding frequency, peak flow or detrusor pressure was seen in either group. Of 15 subjects 4 (26%) receiving botulinum-A toxin had a post-void residual volume of 200 cc or greater and 1 subject required intermittent catheterization. Four subjects experienced a urinary tract infection, 2 (13%) in the botulinum-A toxin group and 2 (28%) in the placebo group (not significant).

Botulinum-A toxin can significantly reduce urge urinary incontinence due to overactive bladder at 6 weeks. However, there is a risk of urinary retention requiring self-catheterization.