Is mirabegron equally as effective when used as first- or second-line therapy in women with overactive bladder?

No previous studies have investigated the efficacy of mirabegron 50 mg as the first-line therapy in OAB patients. Hence, the primary objective of this study was to evaluate the efficacy of mirabegron in treatment-naive patients in comparison with those who had discontinued antimuscarinic therapy because of insufficient efficacy.

All consecutive women who had pure OAB symptoms (including urgency with or without urgency incontinence and frequency) for at least 3 months were considered for this study. Women were divided into two groups: women without any previous pharmacological treatment for OAB (group 1) and women with a previous history of failed antimuscarinics therapy (group 2).

At 3-month follow-up, the objective results on the basis of the frequency-volume chart showed a significant improvement in both groups. Furthermore, a significant reduction in the Overactive Bladder Questionnaire Short Form (OABq-SF) score and in the Indevus Urgency Severity Scale (IUSS) questionnaire were reported in both groups. However, the improvement in objective and subjective outcomes was superior in group 1 to that in group 2.

Mirabegron is efficacious in improving OAB symptoms in both naïve patients and those who discontinued primary antimuscarinic therapy; however, its efficacy is superior when prescribed as first-line therapy.