No financial support was obtained from industry. The authors have no financial interest in any of the products used or mentioned in this study.
Impact of Dry Ejaculation Caused by Highly Selective α1A-blocker: Randomized, Double-blind, Placebo-controlled Crossover Pilot Study in Healthy Volunteer Men
Article first published online: 19 JAN 2010
© 2010 International Society for Sexual Medicine
The Journal of Sexual Medicine
Volume 7, Issue 3, pages 1277–1283, March 2010
How to Cite
Shimizu, F., Taguri, M., Harada, Y., Matsuyama, Y., Sase, K. and Fujime, M. (2010), Impact of Dry Ejaculation Caused by Highly Selective α1A-blocker: Randomized, Double-blind, Placebo-controlled Crossover Pilot Study in Healthy Volunteer Men. Journal of Sexual Medicine, 7: 1277–1283. doi: 10.1111/j.1743-6109.2009.01663.x
- Issue published online: 1 MAR 2010
- Article first published online: 19 JAN 2010
- Ejaculatory Disorder;
- Alpha Blockers;
Introduction. Dry ejaculation with loss of seminal emission is reported in patients who have been administered silodosin, an alpha1A-adrenoceptor antagonist.
Aim. 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.
Main Outcome Measures. 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. Shimizu F, Taguri M, Harada Y, Matsuyama Y, Sase K, and Fujime M. Impact of dry ejaculation caused by highly selective α1A-blocker: Randomized, double-blind, placebo-controlled crossover pilot study in healthy volunteer men. J Sex Med 2010;7:1277–1283.