Efficacy of trospium chloride in patients with detrusor instability: a placebo-controlled, randomized, double-blind, multicentre clinical trial

Objectives To assess the efficacy and safety of trospium chloride (TCl, 20 mg twice daily) in the treatment of detrusor instability, compared with pla cebo. Patients and methods In all, 208 patients were allocated at random to eithe r TCl or placebo in a double-blind clinical study; the patients were treate d for 3 weeks. Urodynamic values were measured at the beginning and end of the treatment period. Adverse events were recorded on patient diary cards. A confirmatory adaptive procedure with one planned interim analysis was use d to evaluate efficacy. Results Trospium chloride produced significant improvements in maximum cyst ometric bladder capacity (median treatment effect 22.0 mL, mean 37.3 mL, on e-sided P = 0.0054) and urinary volume at first unstable contraction (media n treatment effect 45.0 mL, mean 63.6 mL, one-sided P = 0.0015). The patien ts' assessment of efficacy showed significantly greater clinical improvemen t in the TCl group than in the placebo group (two-sided P = 0.0047), Furthe rmore, TCl was well tolerated, with similar frequencies of adverse events r eported in both groups (68% in the TCl and 62% in the placebo group). Conclusion Trospium chloride (20 mg twice daily) is an effective and safe o ption for the treatment of detrusor instability.