STUDIES WITH CYPROTERONE-ACETATE FOR MALE CONTRACEPTION

Daily administration of 10 and 5 mg of cyproterone acetate (CA) to two groups of normal volunteers over a period of 28 weeks caused a gradual decrease in the count and motility of the spermatozoa, with a concomitant increase in the percentage of non-motile as well as abnormal and immature sperms. The ability of motile spermatozoa in the ejaculate to penetrate through preovulatory cervical mucus was markedly inhibited. The levels of acid phosphatase, sialic acid and glycerylphosphorylcholine in the semen decreased progressively, whereas the levels of fructose did not show any significant change. The levels of plasma testosterone were decreased in both the groups. However, the libido and potency were not significantly altered. The liver and kidney functions were not affected. Following cessation of drug therapy the changes in various parameters gradually reversed towards normal values, although some of the parameters did not reach the control level by the 12-18th weeks. In another group of three normal volunteers, who had received 10 mg of CA daily for 12-16 weeks resulting in a marked decrease in the count, motility and cervical mucus penetrating ability of the spermatozoa, and in the biochemical constituents of the semen, subsequent concurrent administration of 75 mg of mesterolone daily for 6-13 weeks counteracted the CA-induced changes very significantly. The possible sites and mode of action of CA and its potential as a male contraceptive are discussed. © 1979.