Comparison of Monotherapies and Combination Therapy of Tamsulosin and Tadalafil for Treating Lower Urinary Tract Symptoms Caused by Benign Prostatic Hyperplasia with or without Erectile Dysfunction: A Meta-Analysis

<b><i>Background:</i></b> There is limited research into the efficacy and safety of tadalafil combined with tamsulosin for the treatment of lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH), with or without erectile dysfunction (ED). Therefore, we aimed to investigate the efficacy and safety of combination therapy compared to that of monotherapy. <b><i>Methods:</i></b> We searched PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, WanFang Data Service Platform, and <ext-link ext-link-type="uri" xlink:href="http://ClinicalTrials.gov" xmlns:xlink="http://www.w3.org/1999/xlink">ClinicalTrials.gov</ext-link> to identify eligible studies. A total of 639 articles were retrieved, of which 12 were randomized controlled trials (RCTs) published as of February 2023 and included in this meta-analysis. <b><i>Results:</i></b> After screening 639 articles, 12 RCTs including 1,531 subjects were considered eligible for the meta-analysis. The results showed that the total International Prostate System Score (total IPSS), maximum flow rate (Qmax), and quality of life (QoL) in tadalafil combined with tamsulosin were significantly better than those in monotherapy. Compared with tadalafil monotherapy, combination therapy mainly improved IPSS voiding. As for postvoid residual urine (PVR), the combination therapy did not improve PVR compared to the tadalafil group, but significantly improved PVR compared to the tamsulosin group. For the International Index of Erectile Function (IIEF), the curative effect of the combined group was better than that of the tamsulosin group but not better than that of the tadalafil group. In terms of safety, the adverse reactions (AEs) in the combined treatment group were significantly higher than those in the monotherapy group. None of the 12 RCTs reported serious adverse events. <b><i>Conclusions:</i></b> Tadalafil combined with tamsulosin was more effective in the treatment of male LUTS/BPH, with or without ED, on the improvement of total IPSS, QoL, and Qmax. However, the benefits of combination therapy for ED remain unclear. However, combination therapy seemed to have a higher incidence of adverse reactions.