Mirabegron for treatment of overactive bladder symptoms in patients with Parkinson's disease: A double-blind, randomized placebo-controlled trial (Parkinson's Disease Overactive bladder Mirabegron, PaDoMi Study)

Aims This study aimed to investigate the efficacy and safety of mirabegron for Parkinsonism patients with overactive bladder (OAB) symptoms in a randomized, placebo-controlled, multicenter study. Materials and methods Inclusion criteria are Parkinsonism with OAB symptoms for 4 weeks or more, OAB symptom score (OABSS) questionnaire scores greater than 2, and OABSS urgency question scores greater than 1. After a 2-week wash-out period, the patients were randomized into placebo and mirabegron groups at visit 2. Visit 3 was performed after 4 weeks of medication. Mirabegron was prescribed to the two groups for the rest of the study period at visit 4. Result The mean age was 68.1 ± 8.1 years and 72 males and 64 females were included. A total of 136 patients were screened, 117 patients were randomized, and 25 patients dropped out. The OABSS scores were significantly different between the two groups at Weeks 4 and 8. The OABSS scores became the same in the two groups at Week 12 (visit 5). The postvoid residual urine volume showed a mild increase to 64 ml in the mirabegron group compared to the placebo group at visit 4. Adverse events occurred in 27 patients (23.1%). The degree was mild in 26 cases (78.8%), moderate in five (15.2%), and severe in two (6.1%). Only 13 cases (39.4%) showed medication-related adverse events. Acute urinary retention occurred in a single case. The treatment satisfaction questionnaires showed no significant differences between the two groups. Conclusion Mirabegron was effective in treating OAB symptoms in patients with Parkinsonism with acceptable adverse events.