The Efficacy of Tamsulosin Monotherapy and Its Combination with Mirabegron for Overactive Bladder Induced by Benign Prostatic Hyperplasia

Abstract Background Alpha 1 adrenoceptor antagonists such as (tamsulosin) are developed for treating of overactive bladder (OAB) associated with benign prostatic hyperplasia (BPH), Acting by blockage of adrenoceptors so can cause relaxation of smooth muscle of the bladder neck and prostate, resulting in an improvement in urine flow and reduction in lower urinary tract symptoms (LUTS). Recently the beta-3 adrenoceptor agonist (mirabegron) has been shown to treat the(OAB) symptoms act by relaxation of detrusor smooth muscle of the bladder, increase the bladder capacity and minimize lower urinary tract symptoms (LUTS) that is associated with (BPH) with less side effect than other pharmacotherapies. We will study the efficacy and safety of this combination therapy. Objective To compare the efficacy and safety of the combination therapy mirabegron and tamsulosin versus tamsulosin monotherapy in case of overactive bladder associated with benign prostatic hyperplasia. Material and method this prospective randomized controlled study conducted in 60 patients between ages of 50-70years and complaining of lower urinary tract symptom(LUTS) associated with(BPH) benign prostatic hyperplasia, Before and 12 weeks after mirabegron additional therapy (50 mg once daily), we evaluated the efficacy of this treatment using the Overactive Bladder Symptom Score (OABSS) and International Prostate Symptom Score (IPSS), and changes in the maximum flow rate (Qmax) and post-void residual urine volume (PVR). Results 60 men were enrolled in this study. The combination therapy improved the OABSS, IPSS total score and quality of life(QOL), the QMAX improved after treatment and there was no significant change in PVR. Conclusions Mirabegron add-on therapy was effective for male patients whose having LUTS particulary the OAB symptoms and storage symptoms that was not controlled by tamsulosin monotherapy with no effect on voiding function therefore the combination therapy considered effective more than monotherapy.