Effects of dutasteride on sex hormones and cerebrospinal steroids in patients treated for benign prostatic hyperplasia.

Abstract

Neuroactive steroids may have a role in regulating sexual function. This case-control study assessed whether dutasteride, a 5α-reductase inhibitor used for treatment of patients with benign prostate hyperplasia (BPH), impacts on the levels of neuroactive steroids, leading to erectile dysfunction (ED) and/or hypoactive sexual desire (HSD). Forty patients with BPH and moderate-to-severe lower urinary tract symptoms (LUTS), pre-scheduled for prostate transurethral resection or open prostatectomy were enrolled. Twenty of these patients with prostate volume ≤40 mL were treated with α-blockers (Group A) and the remaining 20, with prostate volume >40 mL, with dutasteride plus α-blockers (Group B) for at least 6 months before surgery. Serum sex steroids and gonadotropin levels were measured the day before surgery, and the neuroactive steroid levels were assessed in the cerebrospinal fluid (CSF) collected during spinal anesthesia, at the day of surgery. Before surgery, the International Index of Erectile Function 5-item score was higher in Group A that Group B (18.8 ± 4.8 vs. 15.1 ± 5.4, p < 0.01). Group A showed lower total testosterone (TT) (4.5 vs.6.4 ng/ml, p < 0.01) and 17β-estradiol (E2) (24.3 vs.30.7 pg/ml, p < 0.05) serum levels than Group B. CSF levels of TT (1446.6 vs. 19.9 pg/ml, p < 0.05) and dihydrotestosterone (7.9 vs. 1.4 pg/ml, p < 0.05) were higher and CSF E2 levels were lower (26.0 vs.36.0 pg/ml, p < 0.01) in Group A than Group B. A decrease of neuroactive steroids in the CSF of patients treated with dutasteride occurs. This may be one of the mechanisms by which dutasteride may cause ED and HSD.