Efficacy and safety of Finasteride (5 alpha-reductase inhibitor) monotherapy in patients with benign prostatic hyperplasia: A critical review of the literature

BACKGROUND: Combination therapy with 5 alpha-reductase inhibitor (5-ARI) and alpha-blocker can be considered as a gold standard intervention for medical management of lower urinary tract symptoms related to benign prostatic hyperplasia (LUTS/BPH). On the other hand, 5-ARI monotherapy and in particular Finasteride alone is currently getting focus of attention especially due to lack of systematic reviews investigating efficacy outcomes and/or adverse events associated. OBJECTIVES: Aim of the present critical review was to analyze current knowledge of clinical efficacy and incidence of adverse events associated with 5-ARI treatment for LUTS/BPH. MATERIALS AND METHODS: A systematic review of clinical trials of the literature of the past 20 years was performed using database from PubMed, Cochrane Collaboration and Embase. A total of 8821 patients were included in this study and inclusion criteria for studies selection were: data from randomized clinical trials (RCTs) focusing their attention on the clinical role of Finasteride monotherapy for symptomatic BPH. Parameters of research included prostate specific antigen (PSA), prostate volume (PV), International Prostate Symptom Score (IPPS), postvoid residual urine (PVR), voiding symptoms of IPSS (voiding IPSS), maximum urinary flow rate (Qmax), and adverse events (AEs). RESULTS: Overall 12 original articles were included and critically evaluated. Sample sizes of patient actively treated with finasteride varied from 13 to 1524 cases analyzed in a single study. Follow-up after treatments ranged from 3 to 54 months. The effect of finasteride in reducing prostate volume (PV) was moderate (standardized mean difference (SMD) effect between 0.5 to 0.8 for all trials evaluable) while the effect on IPSS score and Qmax was considered significant (SMD in the 0.2 to 0.5 variation range). No severe AEs and/or psychiatric disorders were retrieved among the studies. Sexual health dysfunctions were significantly influenced by finasteride therapy when compared with placebo treated patients. CONCLUSIONS: Although significant clinical benefits of finasteride monotherapy were demonstrated, the effective size of the available reports included in the analysis is limited. Additional head-to-head studies would be needed to re-evaluate clinical efficacy and safety of 5-ARI in combination or not with alpha blockers.