title: Impact of dry ejaculation caused by highly selective alpha1A-blocker: randomized, double-blind, placebo-controlled crossover pilot study in healthy volunteer men.
abstract: BACKGROUND
  Dry ejaculation with loss of seminal emission is reported in patients who have been administered silodosin, an alpha1A-adrenoceptor antagonist.
  
  
  OBJECTIVE
  We investigated the impact of dry ejaculation caused by orally administered silodosin on orgasmic function.
  
  
  METHODS
  In a double-blind crossover study, 50 healthy volunteer men were randomly assigned to receive either a single dose of 4-mg silodosin or placebo with 3 days of washout before crossover. Subjects masturbated 4 hours after administering agents.
  
  
  METHODS
  Numerical rating scale (NRS) score from 0 (highest) to 10 (lowest) for subjective quality of orgasm, the subjective number of contractions of the bulbocavernosus/pelvic floor muscles, and the amount of semen were examined. Results. After the administration of silodosin, the NRS score worsened by 1.3 points (P = 0.003), the number of contractions of the bulbocavernosus/pelvic floor muscles decreased by about 1 (P = 0.003), and there was a decrease of 1.8 mL in the amount of semen produced (P < 0.0001). Eleven men overall (22%) on silodosin administration had less than a 50% decrease from baseline in the amount of semen.
  
  
  CONCLUSIONS
  Silodosin may adversely affect the subjective orgasmic function by causing an abnormal ejaculation with decreased (or no) semen discharge and a decrease in the number of bulbocavernosus/pelvic floor muscle contractions. Semen passing through the urethra and sufficient rhythmic contraction of the muscle of the pelvic floor may contribute to the subjective pleasure of orgasm.
authors.affiliation: Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan. fshimizu-jua@umin.ac.jp
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Shimizu
authors.forename: Masataka
authors.initials: M
authors.lastname: Taguri
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Harada
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sase
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujime
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000009:adverse effects*; D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004542:Ejaculation / Q000187:drug effects*; D006304:Health Status; D006801:Humans; D007211:Indoles / Q000009:adverse effects*; D008297:Male; D010865:Pilot Projects; D012661:Semen / Q000187:drug effects*; D012720:Severity of Illness Index; D020018:Sexual Dysfunctions, Psychological / Q000139:chemically induced* / Q000175:diagnosis; D011795:Surveys and Questionnaires
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D007211:Indoles; C095285:silodosin