Randomized, controlled pilot trial of solifenacin succinate for overactive bladder in Parkinson's disease.

OBJECTIVE: To evaluate the efficacy of solifenacin succinate in Parkinson's disease (PD) patients suffering from overactive bladder (OAB). BACKGROUND: Urinary dysfunction is a commonly encountered non-motor feature in PD that significantly impacts patient quality of life. DESIGN/METHODS: This was a double-blind, randomized, placebo-controlled, 3-site study with an open label extension phase to determine the efficacy of solifenacin succinate in idiopathic PD patients with OAB. Patients were randomized to receive solifenacin succinate 5-10 mg daily or placebo for 12 weeks followed by an 8-week open label extension. The primary outcome measure was the change in the mean number of micturitions per 24 h period. Secondary outcome measures included the change in the mean number of urinary incontinence episodes and the mean number of nocturia episodes. RESULTS: Twenty-three patients were randomized in the study. There was no significant improvement in the primary outcome measure in the double-blind phase, but there was an improvement in the number of micturitions per 24 h period in the solifenacin succinate group compared to placebo at a mean dose of 6 mg/day (p = 0.01). In the open label phase, the mean number of urinary incontinence episodes per 24 h period decreased (p = 0.03), as did the number of nocturia episodes per 24 h period (p = 0.01). Adverse events included constipation and xerostomia, which resolved after treatment was discontinued. CONCLUSIONS: In this pilot trial, solifenacin succinate treatment led to an improvement in urinary incontinence, despite persistence in other OAB symptoms.