Blood loss and postoperative complications associated with transurethral resection of the prostate after pretreatment with dutasteride

OBJECTIVE To determine whether pretreatment with dutasteride, a dual 5 alpha-reductase inhibitor (5ARI), reduces surgical blood loss or postoperative complications in patients with benign prostatic hyperplasia (BPH) who undergo transurethral resection of the prostate (TURP). PATIENTS AND METHODS This double-blind, randomized, placebo-controlled, multicentre study comprised 214 patients with BPH. Placebo was compared with dutasteride 0.5 mg/day 2 weeks before and after TURP, or 4 weeks before and 2 weeks after TURP. Surgical blood loss was measured using a haemoglobin photometer (HemoCue AB, Angelholm, Sweden) and postoperative adverse events were recorded. Microvessel density (MVD) was calculated by immunostaining and light microscopy of the prostatic chips. RESULTS Although dutasteride reduced serum dihydrotestosterone (DHT) by 86-89% in 2-4 weeks, and intraprostatic DHT was approximate to 10 times lower than in the placebo group, the (adjusted) mean haemoglobin (Hb) loss during surgery was 2.15-2.55 g Hb/g resectate with no significant difference in blood loss between the groups either during or after TURP. Clot retention occurred in 6-11% and urinary incontinence in 14-15% of patients during the 14 weeks after TURP, with no difference between the groups. The MVD at TURP was also similar for all groups. CONCLUSION There were no significant reductions in blood loss during or after TURP or complications afterward with dutasteride compared with placebo, despite significant suppression of intraprostatic DHT. Blood loss and transfusion rates in the placebo group were lower than those previously reported in studies where there was a beneficial effect of a 5ARI, relative to placebo, on bleeding during TURP.