Therapeutic efficacy of mirabegron 25 mg monotherapy in patients with nocturia-predominant hypersensitive bladder.

Objective: The objective of this study was to evaluate the efficacy of mirabegron 25 mg daily in patients with nocturia-predominant hypersensitive bladder (HSB).

Materials and methods: This study prospectively investigated 219 consecutive patients with nocturia-predominant HSB and treated with mirabegron 25 mg daily from July 2015 to 2016. Patient with nocturia episode decreased by ≥1/night after treatment was considered successful. The subjective symptom score, such as International Prostate Symptom Score (IPSS), Quality of life index, Overactive Bladder Symptom Score (OABSS), Urgency Severity Scale, patient perception of bladder condition (PPBC), and nocturia episodes per night, was assessed before and 1 month after mirabegron treatment and between successful and failed groups.

Results: A total of 219 patients, including 51 women and 168 men, were enrolled. The mean age of the population was 72.3 ± 11.0 years. Totally, 58 (26.5%) of the patients had improvement in nocturia at 1 month after treatment. Among them, 14 (27.5%) women and 44 (26.2%) men had improvement in nocturia episodes after treatment (P = 0.858). Compared the clinical data between successful and failed group, the baseline symptom scores were more severe in successful group, including IPSS-storage subscore (4.84 ± 2.09 vs. 4.11 ± 2.19, P = 0.031), OABSS (3.21 ± 0.67 vs. 2.91 ± 1.00, P = 0.037), and nocturia episodes (3.81 ± 0.95 vs. 3.095 ± 1.32, P = 0.000). Multivariate analysis revealed only a higher nocturia episodes (P = 0.046) predict a successful treatment result. Mirabegron 25 mg daily significantly improved PPBC score along the 3 months' follow-up (P < 0.05), and postvoid residual volume did not increase after mirabegron treatment in overall patients.

Conclusions: Mirabegron 25 mg daily treatment showed a limited therapeutic effect on nocturia-predominant HSB patients. The patients with higher OAB symptoms predict a successful result.