Efficacy and safety of dose escalation in male patients with overactive bladder showing poor efficacy after low-dose antimuscarinic treatment: A retrospective multicenter study

PURPOSE: To analyze the efficacy and safety of standard-dose antimuscarinic treatment on male patients with overactive bladder (OAB) symptoms showing poor efficacy after low-dose antimuscarinics. MATERIALS AND METHODS: We retrospectively reviewed the data of 566 male patients aged ≥40 with OAB symptoms between January 2017 and June 2018. They were treated with low-dose antimuscarinics for at least 4 weeks and showed poor efficacy; therefore, they were switched to standard dose antimuscarinic treatment (5 mg of solifenacin) for ≥12 weeks. The international prostate symptom score (IPSS) and overactive bladder symptom score (OABSS) at baseline (V0), 4 weeks (V1), and 12 weeks (V2) were analyzed. Post void residual urine volume (PVR) was also recorded. RESULTS: The median age, body mass index, and prostate-specific antigen levels were 69.0 years, 24.2 kg/m(2), and 1.24 ng/dL, respectively. The mean value of the total IPSS and OABSS significantly decreased between V0 and V2 (from 16.73 to 13.69 and 7.33 to 5.34, respectively, all p<0.001). All component scores from each questionnaire demonstrated a significant decrease except for numbers three and six on the IPSS questionnaire. PVR was increased from V0 to V2 (36.40 to 68.90 mL, p=0.015). Four and nine patients experienced constipation and thirst, respectively, and all adverse effects were graded as ≤2. CONCLUSIONS: Standard dose antimuscarinic treatment using solifenacin (5 mg) may be a safe and effective treatment for patients with OAB symptoms refractory to low-dose antimuscarinic treatment.