Comparison of Mirabegron and Vibegron in Women With Treatment-Naive Overactive Bladder: A Randomized Controlled Study

Objective: To compare the efficacy and safety of mirabegron versus vibegron in postmenopausal women with treatment-naïve overactive bladder (OAB).

Methods: We conducted a prospective randomized controlled study of women with treatment-naïve OAB. The patients received mirabegron or vibegron at 50 mg daily for 12 weeks by a stratified randomized method. The OAB symptom score (OABSS) and quality of life (QOL) index were evaluated before and 4 and 12 weeks after the treatment. The patients' 3-day voiding diary and postvoided residual urine volumes were evaluated before and 12 weeks after the treatment.

Results: Of 213 patients initially enrolled in this study, 199 patients were randomized to the mirabegron group (n = 97) or vibegron group (n = 102). Twelve weeks after the treatment, OABSS, QOL index, the numbers of micturition, urgency episodes, incontinence episodes, and voided volume per 24 hours were significantly improved compared with the baseline in both groups, and there was no significant difference in the rate of change in both groups. The postvoid residual urine volume was not significantly different in the 2 groups at 12 weeks. Discontinuation because of adverse effects was observed in 6.2% of patients in the mirabegron group and 6.8% in the vibegron group, with no significant difference between 2 groups.

Conclusion: Both mirabegron at 50 mg and vibegron at 50 mg improved OAB symptoms and the parameters of voiding diary equally in postmenopausal women with treatment naïve OAB.