Treatment of overactive bladder: long-term tolerability and efficacy of tolterodine

Previously available antimuscarinic therapies for overactive bladder are poorly tolerated due to a high incidence of adverse events, notably dry mouth. Tolterodine is a bladder-selective, antimuscarinic agent for the treatment of frequency, urgency, and urge incontinence that characterize overactive bladder. In a 9-month open-label study, the safety, tolerability, and clinical efficacy of tolterodine 2 mg twice daily was evaluated in 854 patients with overactive bladder symptoms who had completed one of four 12 week randomized, controlled trials of tolterodine. Safety and tolerability were assessed in terms of adverse events and clinical/laboratory variables. Efficacy was assessed using micturition diaries and patient perception of their bladder condition. In all, 70% of patients remained on treatment for 9 months. Dry mouth was the most frequently reported adverse event, occurring in 28% of patients (intensity: 19% mild, 7% moderate, 2% severe). A total of 9% of patients withdrew due to adverse events. Dosage reduction occurred in 13% of patients. Significant improvements (P < 0.0001) in micturitions per 24 h (-22%), urge incontinence episodes per 24 h (-76%) and volume voided per micturition (+22%) were observed after 9 months of treatment, with 65% of patients reporting an improvement in perception of their bladder problems. The incidence of adverse events and improvements in micturition diary variables during open-label treatment were comparable with those observed during a 12 week randomized treatment. It was concluded that tolterodine is well tolerated and maintains its clinical efficacy during 9 months of treatment. The high proportion of patients remaining on treatment indicates that tolterodine is an effective long-term treatment for overactive bladder.