Objectives: To compare solifenacin succinate (5 and 10 mg once-daily) to placebo and propiverine hydrochloride (20 mg once-daily), respectively, in Japanese patients with overactive bladder syndrome (OAB).
Patients and methods: A multicentre, 12-week, double-blind phase III trial randomized men and women aged > or = 20 years with OAB to solifenacin 5 or 10 mg, propiverine 20 mg, or placebo. Changes at endpoint in number of voids/24 h, urgency, incontinence, urgency incontinence and nocturia episodes, volume voided/void, restoration of continence and quality of life (QoL) were examined.
Results: Of 1593 patients randomized, 1584 were treated; at the endpoint there were greater reductions in mean (sd) voids/24 h with solifenacin 5 mg, at -1.93 (1.97), and 10 mg, at -2.19 (2.09), and propiverine 20 mg, at -1.87 (2.70), than with placebo, at -0.94 (2.29) (P < 0.001 for all). Solifenacin (5 and 10 mg) was superior to placebo, and no worse than propiverine 20 mg, for this variable. There were significantly fewer mean (sd) urgency, incontinence and urgency incontinence episodes with solifenacin and propiverine than with placebo, with respective changes on placebo of - 1.28 (2.90), - 0.72 (1.95) and - 0.69 (2.00); solifenacin 5 mg, - 2.41 (2.88), -1.59 (2.12) and -1.45 (1.89) (P < 0.001 for all), and 10 mg, -2.78 (2.82), - 1.60 (1.81) and - 1.52 (1.77) (P < 0.001 for all), and propiverine 20 mg, -2.30 (3.08), -1.25 (2.79) and - 1.19 (2.20) (P < 0.001, = 0.002 and = 0.002 respectively). All active treatments vs placebo improved the volume voided (P < 0.001 for all) and QoL; solifenacin 10 mg reduced nocturia episodes (P = 0.021) and significantly improved urgency episodes (P = 0.012) and volume voided (P = 0.009) vs propiverine 20 mg, and solifenacin 5 mg caused less dry mouth (P = 0.003). Solifenacin 10 mg caused more dry mouth (P = 0.012) and occurrences of constipation (P = 0.004) than propiverine 20 mg, but discontinuation rates between both treatment groups were similar. Continence was restored at endpoint in more than half of the patients on active treatment.
Conclusion: Solifenacin 5 and 10 mg once daily significantly improved the symptoms of OAB compared with placebo. Solifenacin therapy at 5 mg once daily is well-tolerated; 10 mg can be given if additional efficacy is required.