Low-dose oxybutynin for the treatment of urge incontinence: Good efficacy and few side effects

Objective: Oxybutynin is an efficacious pharmacotherapeutic agent for the t reatment of urge incontinence. However, many patients discontinue therapy b ecause of the considerable side effects. This study aims at assessing the e fficacy of a low-dose oxybutynin (2.5 mg three times daily) in relation to the concomitant profile of side effects. Methods: Unselected primary care practice patients with involuntary urine l oss were eligible for this study. A specialty designed questionnaire was us ed to establish the diagnosis of symptomatic urge incontinence. All patient s started with an oral dose of oxybutynin of 2.5 mg three times daily, and the responses with regard to efficacy and side effects were assessed after 2 and 6 weeks. Efficacy was evaluated using subjective patients' impression as well as data extracted from their voiding diaries. Adverse events possi bly related to the use of oxybutynin were specifically asked for. Patients who experienced little or no symptomatc relief and who experienced no side effects were given a higher dose (5 mg three times daily). Results: General practitioners recruited 416 patients with symptomatic urge incontinence. Increasing the dose to 5 mg three times was preferred by 115 patients (28%). After 6 weeks 393 patients reported a partial or complete symptomatic cure (positive responder rate 95%). The average number of mictu ritions per 24 h decreased from 9.9+/-(SD)3.7 to 6.0+/-2.5 (p<0.004), and t he average number of episodes of urine loss per 24 h decreased from 6.0+/-3 .6 to 1.7+/-1.8 (p<0.001). A total of 123 patients (30%) reported side effe cts attributable to the rise of oxybutynin; 42 patients (10%) had to stop t he medication because of the severity of these side effects. Conclusion: Successful pharmacological treatment of symptomatic urge incont inence can be given in a primary care setting using oxybutynin. Starting wi th a low dose of 2.5 three times daily, a subjective and objective efficacy can be achieved with fewer side effects than reported in the literature. C opyright (C) 2000 S. Karger AG, Basel.