Inhibition of Seminal Emission Is the Main Cause of Anejaculation Induced by a New Highly Selective α1A-Blocker in Normal Volunteers

Abstract

Introduction Recent studies have highlighted the influence of α1-adrenoceptor antagonists on ejaculatory function. Aim We evaluated the effect of a new, highly selective α1A-blocker, silodosin, on ejaculatory function of normal volunteers. Methods The study included 15 healthy male urologists who voluntarily participated in the study. They took 4 mg of silodosin or a placebo twice daily for 3 days in a randomized, double-blind crossover design. Main Outcome Measures We investigated the ejaculatory volume, sperm count in urine after ejaculation, and fructose concentration in seminal plasma before and after administration of the agents. Results All volunteers on silodosin had a complete lack of ejaculation. Three days after completion of silodosin, the mean ejaculatory volume recovered to the baseline level. There was no sperm in urine after ejaculation under silodosin administration in any volunteer. Conclusions All volunteers on silodosin had anejaculation and did not show post-ejaculate sperm in their urine. The mechanism of ejaculatory dysfunction caused by silodosin is a loss of seminal emission.

Orgasm is preserved regardless of ejaculatory dysfunction with selective α1A-blocker administration

“…Details of ejaculatory profiles and methods of collection have been described earlier. 8 In brief, this study used a double-blind, placebo controlled, randomized, crossover design ( Figure 1). The median age of the participants was 32 years (range 26-47 years).…”

“…We defined anejaculation as a 100% decrease in ejaculation volume compared with the baseline ejaculatory profile as in earlier reports. 6,8 After each ejaculation, participants self-reported the answers to an original questionnaire composed of questions to evaluate ejaculatory function, including orgasm and feeling (see Appendix). All samples were collected by masturbation.…”

“…[1][2][3][4][5] Recent studies have highlighted the influence of a1-blockers on ejaculatory function. [6][7][8][9][10] A loss of seminal emission has been recently postulated as one of the mechanisms of abnormal ejaculation. 7,8 Highly selective a1-adrenoceptor subtype-A antagonists (a1A-blockers) cause a high incidence of ejaculatory dysfunction.…”

“…[6][7][8][9][10] A loss of seminal emission has been recently postulated as one of the mechanisms of abnormal ejaculation. 7,8 Highly selective a1-adrenoceptor subtype-A antagonists (a1A-blockers) cause a high incidence of ejaculatory dysfunction. However, the orgasm and feeling during ejaculatory dysfunction with a1-blocker administration have not been fully assessed.…”

“…16 We reported earlier that silodosin induced a complete lack of seminal emission in healthy volunteers. 8 In this context, we evaluated the status of orgasm and feeling during ejaculatory dysfunction induced with the selective a1A-blocker in healthy volunteers.…”