Silodosin (Sil)

Silodosin is a medication for the symptomatic treatment of benign prostatic hyperplasia. It acts as an α1-adrenoceptor antagonist with high uroselectivity (selectivity for the prostate). Since silodosin has high affinity for the α1A adrenergic receptor, it causes practically no orthostatic hypotension (in contrast to other α1 blockers). On the other side, the high selectivity seems to cause more problems with ejaculation. As α1A adrenoceptor antagonists are being investigated as a means to male birth control due to their ability to inhibit ejaculation but not orgasm, a trial with 15 male volunteers was conducted. While silodosin was completely efficacious in preventing the release of semen in all subjects, 12 out of the 15 patients reported mild discomfort upon orgasm. The men also reported the psychosexual side effect of being strongly dissatisfied by their lack of ejaculation.