TAMSULOSIN, A SELECTIVE ALPHA(1)-ADRENOCEPTOR ANTAGONIST, INHIBITS FERTILITY OF MALE-RATS

This study examined the antifertility effects of tamsulosin, a highly potent and a selective, alpha(1)-adrenoceptor antagonist, on male rats . The drug was administered subcutaneously as a single dose (0.15 mg k g(-1)). The drug caused a significant reduction in fertility (measured by number of uterine implants, quantal pregnancy, and fertility index ). The antifertility effect was short lived and rapid in both onset (n o later than 7 h of administration) and recovery (within 7 d). Libido and mating performance remained essentially uninhibited. On the other hand, the antifertility effect was accompanied by significant impairme nt in ejaculatory competence and enhancement of pre-implantation losse s. Based on the results of this study and our previous studies it is c oncluded that alpha 1-adrenoceptor blockade has a potent antifertility effect in male rats.