Prospective randomized controlled trial of extended-release oxybutynin chloride and tolterodine tartrate in the treatment of overactive bladder: results of the OBJECT Study

To compare the efficacy and tolerability of extended-release oxybutynin chloride and tolterodine tartrate at 12 weeks in participants with overactive bladder. The OBJECT (Overactive Bladder: Judging Effective Control and Treatment) study was a prospective, randomized, double-blind, parallel-group study conducted between March and October 2000 at 37 US study sites. Participants who had between 7 and 50 episodes of urge incontinence per week and 10 or more voids in 24 hours received extended-release oxybutynin, 10 mg/d, or tolterodine, 2 mg twice daily. The outcome measures were the number of episodes of urge incontinence, total incontinence, and micturition frequency at 12 weeks adjusted for baseline. A total of 315 women and 63 men were randomized and treated, and 332 participants (276 women, 56 men) completed the study. At the end of the study, extended-release oxybutynin was significantly more effective than tolterodine in each of the main outcome measures: weekly urge incontinence (P=.03), total incontinence (P=.02), and micturition frequency episodes (P=.02) adjusted for baseline. Both drugs improved symptoms of overactive bladder significantly from baseline to the end of the study as assessed by the 3 main outcome measures (P