Efficacy and tolerability of treatment with mirabegron compared with solifenacin in the management of overactive bladder syndrome: a prospective comparative study

Aim: The aim of this study is to compare the efficacy and tolerability of solifenacin and mirabegron in patients with overactive bladder (OAB) syndrome.
Methods: We carried out a prospective randomized double blind comparative analysis in 342 women affected by OAB syndrome; 168 were treated with solifenacin 5 mg/daily and 174 with mirabegron 50 mg/daily. A clinical evaluation, 3-day voiding diary, and urodynamic testing was performed. Patients completed the Overactive Bladder Questionnaire - Short Form and the Patient Global Impression of Improvement questionnaire. The adverse effects were evaluated. The two groups were compared at baseline and at 12 weeks.
Results: After 12 weeks, a significant reduction in the mean number/24 h of voids and urgent micturition episodes/24 h was observed in both groups. Detrusor overactivity decreased from 58.3% to 13.1% in the solifenacin group and from 58% to 11% in the mirabegron group. Twenty (12%) and 18 (10.7%) patients taking solifenacin reported constipation and dry mouth, respectively, versus four (2.3%) and five (2.9%) patients taking mirabegron, respectively, but there was no difference between the groups in the change in vital signs.
The Overactive Bladder Questionnaire - Short Form did not demonstrate significant differences and the abandonment rates in the solifenacin and mirabegron groups were 25.5% and 20%, respectively.
Conclusion: Solifenacin and mirabegron showed the same efficacy in the treatment of OAB but solifenacin had more adverse effects.