Bladder instillation of liposome encapsulated onabotulinumtoxina improves overactive bladder symptoms: a prospective, multicenter, double-blind, randomized trial.

PURPOSE Cystoscopic intradetrusor injection of botulinum toxin has helped patients with refractory overactive bladder but with the increased risks of urinary tract infection and urinary retention. We assessed whether catheter instillation of 200 U onabotulinumtoxinA formulated with liposomes is safe and effective for the treatment of overactive bladder. MATERIALS AND METHODS This 2-center, double-blind, randomized, placebo controlled study enrolled patients with overactive bladder inadequately managed with antimuscarinics. Patients were assigned to intravesical instillation of lipo-botulinum toxin (31) or normal saline (31). The primary end point was the mean change in micturition events per 3 days at 4 weeks after treatment. Additional end points included mean changes in urgency events, frequency and urinary urge incontinence, as well as changes in overactive bladder symptom scores and urgency severity scores. RESULTS At 4 weeks after treatment lipo-botulinum toxin instillation was associated with a statistically significant decrease in micturition events per 3 days (-4.64 for lipo-botulinum toxin vs -0.19 for placebo, p = 0.0252). Lipo-botulinum toxin instillation was also associated with a statistically significant decrease in urinary urgency events with respect to baseline but not placebo. However, lipo-botulinum toxin instillation was associated with a statistically significant decrease in urgency severity scores compared to placebo (p = 0.0181). These observed benefits of lipo-botulinum toxin instillation were not accompanied by an increased risk of urinary retention. The effects of lipo-botulinum toxin on urinary urge incontinence were inconclusive. CONCLUSIONS A single intravesical instillation of lipo-botulinum toxin was associated with decreases in overactive bladder symptoms without side effects. Intravesical instillation of liposomal botulinum toxin may be a promising approach to treat refractory overactive bladder.