Twelve-month treatment of overactive bladder: efficacy and tolerability of tolterodine

CONTEXT: Tolterodine is a bladder-selective antimuscarinic agent designed for the treatment of overactive bladder. Traditional antimuscarinic therapies are poorly tolerated due to a high incidence of anticholinergic adverse events and consequently few patients remain on long term therapy. OBJECTIVE: To evaluate the long term efficacy and tolerability of tolterodine in patients with symptoms of overactive bladder. DESIGN: Twelve-month open-label extension of 4 randomised, placebo-controlled, double-blind, multinational, multicentre trials of 4 weeks' duration. PATIENTS: 714 patients (aged 18 to 92 years) with symptoms of overactive bladder who completed the double-blind portion of the studies. INTERVENTION: Tolterodine 2 mg twice daily for up to 12 months. MAIN OUTCOME MEASURES: Micturition diary variables: number of micturitions per 24 hours, number of urge incontinence episodes per 24 hours, mean urine volume voided per micturition. Safety variables: adverse events, study discontinuation rate. RESULTS: A total of 441 patients (62%) completed 12 months' open-label treatment with tolterodine, which significantly reduced the number of micturitions per 24 hours [mean change -2.4, 95% confidence interval (CI) -2.7 to -2.2, median change -20%, p < 0.0001] and number of urge incontinence episodes per 24 hours (mean change -1.3, 95% CI -1.6 to -1.0, median change -74%, p < 0.0001), while the mean volume voided per micturition was significantly increased (+33 ml, 95% CI +28 to +38, median change +18%; p < 0.0001). 41% of patients reported dry mouth (27% mild, 10% moderate, 3% severe). Dosage reduction to 1 mg twice daily was required in 23% of patients. 15% of patients withdrew from the study due to adverse events, with 5% having associated dry mouth. CONCLUSIONS: The high percentage of patients completing 12 months' treatment indicates that tolterodine is an effective and well tolerated agent for long term treatment of overactive bladder.