Mirabegron Add-On Tamsulosin for Men with Overactive Bladder Symptoms: A Pooled Analysis of Four Randomized Controlled Trials.

INTRODUCTION

Overactive bladder symptoms (OABSs) affect patients' quality of life (QOL) worldwide. This pooled analysis compared the efficacy and safety of mirabegron add-on tamsulosin with those of tamsulosin add-on placebo in OABS treatment.

METHODS

PubMed, Embase, MEDLINE, and the Cochrane Controlled Trial Register databases were searched for randomized controlled trials (RCTs) examining the efficacy of mirabegron add-on therapy to tamsulosin in the treatment of OABS. Moreover, references from the selected studies were screened. Review Manager 5.4 was used to analyze data.

RESULTS

Four RCTs involving 1,397 patients with OABS were selected. Of the total, 697 patients receiving mirabegron add-on tamsulosin constituted the experimental group, and 700 patients receiving tamsulosin add-on placebo constituted the control group. The efficacy endpoints were as follows: mean number of micturition per day (mean difference [MD] = -0.26, 95% confidence interval [CI] = -0.41 to -0.10, p = 0.0001), urgency episodes per day (MD = -0.67, 95% CI = -1.02 to -0.32, p = 0.0002), urgency urinary incontinence (UUI) episodes per day (MD = -0.42, 95% CI = -0.66 to -0.19, p = 0.0005), mean volume voided/micturition (MD = 10.84, 95% CI = 4.97-16.71, p = 0.0003), total International Prostate Symptom Score (IPSS) (MD = -2.01, 95% CI = -4.02 to -0.01, p = 0.05), and IPSS QOL index (MD = -0.65, 95% CI = -0.94 to -0.35, p < 0.0001). Mirabegron therapy, an add-on therapy to tamsulosin, was effective in treating patients with OABS. Moreover, mirabegron might reduce the total IPSS (MD = -2.01, 95% CI = -4.02 to -0.01, p = 0.05). The safety endpoint, treatment-emergent adverse events (odds ratio = 0.94, 95% CI = 0.78-1.13, p = 0.49), suggested that although mirabegron was well-tolerated, it possibly increased the post-void residual urine volume (MD = 10.28, 95% CI = 1.82-18.75, p = 0.02).

CONCLUSION

Combination therapy using mirabegron and tamsulosin may be effective in treating patients with non-neurogenic OABS in terms of UUI episodes, total IPSS, and IPSS QOL index. However, its effectiveness must be verified by analyzing additional factors for OABS through further RCTs.