PURPOSE: To evaluate the efficacy and safety of add-on treatment with a β3-adrenoceptor agonist (mirabegron) on overactive bladder (OAB) symptoms remaining after α1-blocker (tamsulosin) treatment in men with benign prostatic obstruction (BPO).
MATERIALS AND METHODS: Patients with BPO having urinary urgency at least once per week and a total OAB symptom score (OABSS) ≥ 3 points after ≥ 8 weeks treatment with tamsulosin were enrolled. They were randomly allocated to receive 0.2 mg of tamsulosin daily or 0.2 mg of tamsulosin and 50 mg of mirabegron daily for 8 weeks. The primary endpoint was the change in the total OABSS. Safety assessments included the change in the post-void residual urine volume (PVR) and adverse events (AEs).
RESULTS: From January 2012 through September 2013, a total of 94 patients were randomized. Of these, 76 completed the protocol treatment. In the full analysis set, the change in the total OABSS during the treatment period was significantly greater in the combination group than in the monotherapy group (-2.21 vs. -0.87, p=0.012). The changes in the scores for urinary urgency, daytime frequency, and the International Prostate Symptom Score storage symptom subscore and QOL for 8 weeks were significantly greater in the combination group. The change in PVR was significantly greater in the combination group. Although 6 patients developed AEs in the combination group, urinary retention was observed in only 1 patient.
CONCLUSION: Combined tamsulosin and mirabegron treatment is effective and safe for patients with BPO who have OAB symptoms remaining after tamsulosin monotherapy.
Written by:
Ichihara K, Masumori N, Fukuta F, Tsukamoto T, Iwasawa A, Tanaka Y. Are you the author?
Department of Urology, Sapporo Medical University School of Medicine; Iwasawa Clinic; Department of Urology, Hokkaido Prefectural Esashi Hospital.
Reference: J Urol. 2014 Sep 21. pii: S0022-5347(14)04488-7.
doi: 10.1016/j.juro.2014.09.091
PubMed Abstract
PMID: 25254938