OnabotulinumtoxinA in urinary incontinence: Prospective Study of a Case Series

To assess the safety and efficacy of a single intravesical injection of onabotulinumtoxinA (OnaBTA) for treating urge urinary incontinence (UUI) in women.

We performed a prospective case-series study of consecutive patients with refractory UUI treated with an intravesical injection of OnaBTA. The patients were administered 100 units of OnaBTA injected into the bladder wall following 4 weeks of flushing with anticholinergic agents or beta 3 agonists. The urodynamic and clinical endpoints were evaluated before and 6 months after the injection of OnaBTA. The primary study endpoint was the number of episodes of urinary leakage.

A total of 204 of the 210 selected patients conducted a valid visit 6 months after the therapeutic application. At 6 months of treatment with OnaBTA, 110 (53.9%) patients remained continent and were considered a success. However, 57 (27.9%) patients experienced one episode of urinary leakage per day, and 37 (18.2%) had 2 or more. In terms of the urodynamic parameters, we observed the following changes: increase in maximum bladder capacity (P<.0001) and reduced maximum pressure of the detrusor (P<.0001). In terms of the safety profile, 8 (3.9%) patients had self-limiting haematuria during the procedure, which resolved spontaneously, and 9 (4.4%) patients had acute urinary retention that required intermittent catheterisation.

This study supports the use of OnabotulinumtoxinA in patients with urge urinary incontinence that does not respond to medical treatment.