Original Article
Prospective Randomized Controlled Trial of Extended-Release Oxybutynin Chloride and Tolterodine Tartrate in the Treatment of Overactive Bladder: Results of the OBJECT Study

https://doi.org/10.4065/76.4.358Get rights and content

Objective

To compare the efficacy and tolerability of extended-release oxybutynin chloride and tolterodine tartrate at 12 weeks in participants with overactive bladder.

Subjects and Methods

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.

Results

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<.001). Dry mouth, the most common adverse event, was reported by 28.1% and 33.2% of participants taking extended-release oxybutynin and tolterodine, respectively (P=.32). Rates of central nervous system and other adverse events were low and similar in both groups.

Conclusions

Extended-release oxybutynin was more effective than tolterodine as measured by end-of-study urge incontinence, total incontinence, and micturition frequency episodes. Both groups had similar rates of dry mouth and other adverse events.

Section snippets

Objectives

This study compared the effect of 12 weeks of treatment with extended-release oxybutynin or tolterodine on episodes of urge incontinence, total incontinence, and micturition frequency episodes, and it evaluated the tolerability of extended-release oxybutynin and tolterodine in participants with overactive bladder.

Participants

Participants with overactive bladder who had between 7 and 50 episodes of urge incontinence per week and 10 or more voids per 24 hours were included. Those with mixed stress and urge

RESULTS

A total of 37 study centers across the United States randomized 378 participants (315 women, 63 men) into the 2 treatment groups; 332 participants (276 women, 56 men) completed the study, and 46 discontinued early. Baseline characteristics were similar between the 2 treatment groups (Table 1); the majority of participants were white (87%) and were naïve to antimuscarinic therapy (60%). Baseline urinary symptoms were also comparable between the 2 groups (Table 2). Reasons for discontinuation

DISCUSSION

The OBJECT trial reports the first use of extended-release oxybutynin in a fixed-dose regimen, and the study design compared 2 antimuscarinic agents used in the treatment of overactive bladder. A placebo arm was not included, as both products were approved by the Food and Drug Administration on the basis of placebo-controlled trials. The double-blind, randomized design of this study limits the potential for treatment selection bias.

The tolerability profile of both drugs in the present study was

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    Greater effects are noted in patients with moderate to severe OAB symptoms at baseline.33 Dry mouth is a common side effect that occurs in one third of patients on tolterodine,34 but it does not increase the number of treatment discontinuations.35 Tolterodine does not seem to cause any cardiovascular or CNS adverse effects.35

  • Traitements visant la vessie hyperactive: Accent sur la pharmacothérapie

    2016, Journal of Obstetrics and Gynaecology Canada
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This study was funded by ALZA Corporation, Mountain View, Calif.

1

Dr Appell is now at Baylor College of Medicine, Houston, Tex. Authors' financial disclosures and a complete list of participants in the OBJECT Study Group appear at the end of this article.

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