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.