Efficacy and Safety of Oxybutynin Topical Gel 3% in Patients With Urgency and/or Mixed Urinary Incontinence: A Randomized, Double-Blind, Placebo-Controlled Study

AimsTo assess the efficacy and safety of oxybutynin transdermal gel 3% (OTG3%), with propylene glycol for enhanced skin permeation, in patients with urinary incontinence (UI). MethodsIn this phase 3 study, 626 patients 18 years old with urgency and/or mixed UI symptoms and predominantly urgency UI for 3 months were randomized 1:1:1 to receive 12 weeks of OTG3% 84mg, OTG3% 56mg, or placebo gel applied once daily to abdomen, inner/upper thigh, or upper arm/shoulder. Primary efficacy endpoint was change from baseline to Week 12 in weekly UI episodes recorded in 3-day bladder diaries. Results were compared using analysis of covariance. Adverse events (AEs) were monitored. ResultsEfficacy was assessed in 601 (intent-to-treat) and safety in 626 patients. At 12 weeks, OTG3% 84mg/day achieved significantly greater improvement versus placebo in weekly UI episodes (mean change from baseline: -20.4 vs. -18.1; P<0.05(a)), daily urinary frequency (-2.6 vs. -1.9; P=0.001(b)), and urinary void volume (32.7 vs. 9.8; P<0.0001(b)). Dry mouth, the most common treatment-related AE, occurred more often with OTG3% 84mg/day (26/214 [12.1%]) vs. placebo (10/202 [5.0%]) (P=0.028); 4 OTG3% patients withdrew because of dry mouth. Application site erythema occurred more often with OTG3% 84mg/day (8/214 [3.7%]) versus placebo (2/202 [1.0%]) (P=NS); 12 OTG patients withdrew because of skin irritation. No serious treatment-related AEs occurred. ConclusionsOTG3% 84mg/day was well tolerated and effective in improving urge incontinence or mixed UI symptoms with a predominance of UI in adults with overactive bladder. Neurourol. Urodynam. 34:37-43, 2015. (c) 2013 Wiley Periodicals, Inc.