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 placebo. Patients and methods In all, 208 patients were allocated at random to either TCl or placebo in a double-blind clinical study; the patients were treated 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 used to evaluate efficacy. Results Trospium chloride produced significant improvements in maximum cystometric bladder capacity (median treatment effect 22.0 mL, mean 37.3 mL, one-sided P = 0.0054) and urinary volume at first unstable contraction (median treatment effect 45.0 mL, mean 63.6 mL, one-sided P = 0.0015). The patients' assessment of efficacy showed significantly greater clinical improvement in the TCl group than in the placebo group (two-sided P = 0.0047), Furthermore, TCl was well tolerated, with similar frequencies of adverse events reported 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 option for the treatment of detrusor instability.