Efficacy and Safety of Oxybutynin Chloride Topical Gel for Overactive Bladder: A Randomized, Double-Blind, Placebo Controlled, Multicenter Study

Purpose: We assessed the efficacy and safety of oxybutynin chloride topical gel vs placebo in adults with overactive bladder. Materials and Methods: Men and women 18 years or older with urge predominant urinary incontinence were enrolled in randomized, parallel group, double-blind, placebo controlled Study OG05009 done at 76 clinics in the United States. Eligible patients were assigned to receive 1 gin oxybutynin chloride topical gel (10% weight per weight ethanol based formulation of oxybutynin) or matching placebo once daily for 12 weeks. Efficacy was assessed using data from 3,day urinary diaries and the primary outcome was the change from baseline in the number of urge incontinence episodes. Safety was monitored through adverse event reporting. Efficacy results in the oxybutynin chloride topical gel and placebo groups were compared by ANCOVA with last observations carried forward. Results: A total of 789 randomized patients, including 704 women (89.2%), with a mean age of 59 years were assigned to treatment with oxybutynin chloride topical gel (389) or placebo (400). The mean number of urge incontinence episodes decreased significantly more in patients treated with oxybutynin chloride topical gel than in those given placebo (-3.0 vs -2.5 per day, p < 0.0001). Mean urinary frequency decreased (-2.7 per day, p = 0.0017) and voided volume increased (21.0 ml, p = 0.0018) significantly more in the oxybutynin chloride group than in the placebo group (-2.0 per day and 3.8 ml, respectively). Treatment related dry mouth was more frequent in the oxybutynin chloride group than in the placebo group (27 of 389 patients or 6.9% vs 11 of 400 or 2.8%). Application site reactions were infrequently observed in the oxybutynin chloride and placebo groups (21 of 389 patients or 5.4% and 4 of 400 or 1.0%, respectively). No serious treatment related adverse events occurred. Conclusions: Oxybutynin chloride topical gel was efficacious in improving overactive bladder symptoms and was well tolerated in adult patients.