Urodynamic Efficacy and Safety of Mirabegron Add-on Treatment with Tamsulosin for Japanese Male Patients with Overactive Bladder

Objectives To investigate urodynamic efficacy and safety of mirabegron add‐on treatment with tamsulosin for Japanese male patients with overactive bladder (OAB). Methods A prospective study was conducted in 26 consecutive male patients with OAB who had been taking tamsulosin. OAB was diagnosed by overactive bladder symptom score (OABSS). Before and 8 weeks after mirabegron add‐on treatment with preceding tamsulosin, we assessed OABSS, International Prostate Symptom Score (IPSS), free uroflowmetry (UFM), filling cystometry and pressure‐flow study (PFS). Results Mean age and prostate volume of the study patients were 75 ± 7 years and 32 ± 19 mL, respectively. Mirabegron significantly improved OABSS (from 8.5 ± 2.3 to 4.7 ± 2.5, P