Tolterodine - A review of its use in the treatment of overactive bladder

Tolterodine is a competitive muscarinic receptor antagonist that shows in vivo selectivity for the bladder over the salivary glands compared with oxybutinin. Results of randomised double-blind placebo-controlled studies indicate that tolterodine 4 mg/day (administered as immediate-release tablets 2 mg twice daily or extended-release capsules 4 mg daily) is superior to placebo in improving micturition diary variables in patients with overactive bladder. Moreover, tolterodine 2 mg twice daily is as effective as oxybutynin 5 mg 3 times daily. Maximum treatment effects with both drugs occurred after 5 to 8 weeks of treatment and improvements were maintained during long term treatment for up to 24 months. In a pooled analysis of four 12-week studies, equivalent and significant reductions in micturition frequency (-2.3 and -2.0 vs -1.4, p < 0.001) and the incidence of urge incontinence episodes (-1.6 and -1.8 vs -1.1, p < 0.05) were reported fur tolterodine 2 mg twice daily and oxybutynin 5 mg 3 times daily compared with placebo. Functional bladder capacity was also significantly increased. Improvements in patient perceptions of their urgency symptoms and of problems caused by their bladder condition were significantly greater during treatment with tolterodine than with placebo, Tolterodine was generally well tolerated in clinical trials of up to 24 months' duration. Dry mouth was the most frequent adverse event, The incidence (40 vs 78%, p < 0.001) and intensity of this event was lower with tolterodine 2 mg twice daily than oxybutynin 5 mg 3 times daily. Additionally, a 23% lower incidence of dry mouth was reported with once daily extended-release tolterodine capsules than with twice daily immediate-release tablets (p < 0.02). The incidence of adverse CNS events with tolterodine was low and similar to that of placebo, Tolterodine was well tolerated in elderly patients and no serious tolerability concerns were identified.