The role of 5‐alpha reductase inhibitors in transurethral resection of the prostate: a meta‐analysis of randomised controlled trials

Objective To critically evaluate the existing evidence base surrounding the efficacy of preoperative 5‐alpha reductase inhibitor (5ARI) administration in the reduction of perioperative complication rates in transurethral resection of prostate (TURP). Methods In April 2025, a systematic search of on‐line databases was conducted to identify randomised controlled trials (RCTs) that compared surgical outcomes and complication rates in patients undergoing TURP for benign prostatic hyperplasia (BPH) who were treated preoperatively with 5ARI (finasteride or dutasteride) as compared to placebo/none. The efficacy of preoperative finasteride was evaluated through outcomes related to blood loss, rate of blood transfusion, and operative time. The physiological mechanism of 5ARI treatment was evaluated through microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression of the resected specimen. Results A total of 30 RCTs met the inclusion criteria for this meta‐analysis in which a total of 2974 patients underwent TURP for BPH (1464 5ARI: 1410 Control). Intraoperative blood loss was significantly lower among 5ARI‐treated patients ( Z = 6.37, mean difference [MD] = −82.58 mL, 95% confidence interval [CI] −107.98 to −57.18; P < 0.001), which was reflected in a significantly lesser haemoglobin drop on the first postoperative day ( Z = 6.84, MD = −0.90 g/dL, 95% CI−1.16 to −0.64; P < 0.001). The MVD was significantly lower in resected specimens from 5ARI‐treated patients (MD = −6.18 vessels/mm 3 , P < 0.001), whilst expressing significantly less VEGF (MD = −3.25, P < 0.001). Patients treated with 5ARI required blood transfusion less frequently than controls (odds ratio 0.31, P < 0.001). The use of 5ARI was associated with shorter operative time (MD = −3.47 min, P = 0.02) and lower volume of irrigation agents (MD = –2.07 L, P < 0.001). Conclusion Preoperative administration of 5ARIs significantly reduces intraoperative blood loss and risk of requiring blood transfusion in patients undergoing TURP for BPH. Even short durations (2 weeks) of 5ARI therapy can significantly reduce prostate vascularity.