title: Effects of testosterone on erectile function: implications for the therapy of erectile dysfunction.
abstract: Sexual potency declines with age, as does the efficiency of erection. Many studies show that different patterns of erectile dysfunction (ED), varying from occasional inability to obtain a full erection, impairment throughout intercourse and total absence of erectile response, might not be triggered by psychological factors only. Recent research indicates that ED relies on organic causes, and has challenged the development of new therapies. One therapeutic approach in patients who have testosterone deficiency is based on androgen therapy. Thus, we reviewed data on testosterone-induced effects relative to erectile function, summarizing the results from studies reported in 1991-2006 on testosterone therapy in patients with ED and hypogonadism, with a special focus on men not responding to phosphodiesterase-5 (PDE-5) inhibitors. We searched several computerized databases parallel with printed bibliographic references. Many studies have established animal models, which confirm that testosterone is important in modulating the central and peripheral regulation of ED. Testosterone deprivation has a strong negative impact on the structure of penile tissues and erectile nerves, which can be prevented by androgen administration. Combined therapy regimens with PDE-5 inhibitors and testosterone might improve ED in patients with hypogonadism of different causes. Thus, androgen treatment in hypogonadic patients, including those unresponsive to PDE-5 inhibitors, often results in an improvement of ED. Testosterone therapy is safe and convenient, while rapidly correcting low testosterone levels.
authors.affiliation: GBU Gynecology-Andrology, Bayer Schering Pharma, Berlin, Germany. Farid.Saad@Schering.de
authors.forename: Farid
authors.initials: F
authors.lastname: Saad
authors.forename: Anca S
authors.initials: AS
authors.lastname: Grahl
authors.forename: Antonio
authors.initials: A
authors.lastname: Aversa
authors.forename: Aksam A
authors.initials: AA
authors.lastname: Yassin
authors.forename: Ates
authors.initials: A
authors.lastname: Kadioglu
authors.forename: Atez
authors.initials: A
authors.lastname: Kadioglu
authors.forename: Ignacio
authors.initials: I
authors.lastname: Moncada
authors.forename: Ian
authors.initials: I
authors.lastname: Eardley
mesh_terms: D000375:Aging / Q000502:physiology; D000728:Androgens / Q000627:therapeutic use*; D000818:Animals; D006801:Humans; D007006:Hypogonadism / Q000150:complications / Q000188:drug therapy*; D018783:Impotence, Vasculogenic / Q000150:complications / Q000188:drug therapy*; D008297:Male; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use; D011817:Rabbits; D051381:Rats; D013739:Testosterone / Q000172:deficiency / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000728:Androgens; D010726:Phosphodiesterase Inhibitors; D013739:Testosterone