Pharmacology of male contraception

Abstract

Clinical trials involving estrogen-androgen combinations antispermatogens and until recently gossypol aimed at controlling male fertility have yielded discouraging results. In recent years the discovery that spermatozoa matures in the epididymis has placed considerable attention on the epidymis as an extragonadal site for control of male fertility. Ideally a male contraceptive pill must be effective safe and reasonably quick-acting. Agents which attack maturation and storage of spermatozoa in the epididymis can best fulfill this criteria. One obvious advantage of the epididymal approach is its speed of action: an effect on stored spermatozoa could produce infertility within days while an effect on the testis would need several weeks to suppress spermatogenesis completely. So far chlorohydrin is the most important drug that affects epdidymal maturation of spermatozoa. However recent discovery of its toxic effects in the rhesus monkey at therapeutic doses has dampened interest in its further development as a male contraceptive agent. It appears that the emergence of an effective and safe male contraceptive pill is not imminent. Progress in this area has been hampered by lack of basic knowledge of the male reproductive system. Further research in the processes regulating sperm maturation may lead to the development of a safer and more effective contraceptive method.