title: The effect of 5 alpha-reductase inhibitors on erectile function.
abstract: The 5 alpha-reductase inhibitors, which inhibit conversion of testosterone to dihydrotestosterone, are used for miscellaneous clinical applications, including the treatment of benign prostatic hyperplasia and male pattern hair loss, and for possible reduction of the risk of prostate cancer. Erectile dysfunction has been associated with 5 alpha-reductase inhibitors. Overall, reports in the literature suggest rates of erectile dysfunction to be between 0.8%-33% in men using these medications. However, randomized controlled studies report the rates of erectile dysfunction to be between 0.8%-15.8%. The possible risk association is that these medications impact androgen function, which is understood to contribute to normal erectile physiology. The 5 alpha-reductase inhibitors result in a drop in median serum dihydrotestosterone levels by 60%-93% within 2 years, but there is no major change in testosterone levels. In this review, we surveyed studies on erectile dysfunction in patients treated with 5 alpha-reductase inhibitors and critically examined the evidence that associates 5 alpha-reductase inhibitors and erectile dysfunction. We conclude that 5 alpha-reductase inhibitors do not lead to erectile dysfunction to a significant degree, and we support the position that dihydrotestosterone is less relevant than testosterone in erectile function.
authors.affiliation: The Johns Hopkins Hospital, The James Buchanan Brady Urological Institute, Department of Urology, Marburg 414, 600 North Wolfe Street, Baltimore, MD 21287, USA. ocanguvl@jhmi.edu
authors.forename: Onder
authors.initials: O
authors.lastname: Canguven
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Burnett
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000172:deficiency; D058891:5-alpha Reductase Inhibitors; D000728:Androgens / Q000502:physiology; D000818:Animals; D002986:Clinical Trials as Topic; D013196:Dihydrotestosterone / Q000378:metabolism; D007172:Erectile Dysfunction / Q000188:drug therapy; D006801:Humans; D008297:Male; D023421:Models, Animal; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D013739:Testosterone / Q000502:physiology
chemical_list: D058891:5-alpha Reductase Inhibitors; D000728:Androgens; D013196:Dihydrotestosterone; D013739:Testosterone; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase