Evaluation of steroids as contraceptives in men.

5 clinical studies were conducted to evaluate the potential of steroids as oral contraceptives in men. The aim of the studies was to reduce sperm counts or interfere with sperm maturation without libido loss or cardiovascular side effects. Study 1 sought to determine whether oral testosterone will restore S-testosterone in patients with low endogenous androgen production. S-testosterone levels were found to return to base levels within 12 hours after administration of 100-200 mg of oral testosterone. Since no cumulative effect was noted 100 mg of testosterone twice daily was combined with levonorgestrel to maintain libido and potency. Study 2 sought to select a dose of levonorgestrel which in combination with oral testosterone could reduce sperm count without libido or potency loss. 250 mcg/day of levonorgestrel and oral testosterone decreased the sperm count significantly in 3 out of 4 men but not to oligospermic levels. Study 3 compared the effects of 2 doses of levonorgestrel on sperm count. 250 mcg/day of levonorgestrel plus 200 mg of testosterone ethanate monthly led to severe oligospermia in 2 of 5 men whereas 500 mcg/day of levonorgestrel and 200 mg of testosterone ethnate induced severe oligospermia in 4 of 5 volunteers. 1 volunteer in the latter group experienced depressive mood changes but no other side effects were noted. Study 4 evaluated the effect of the antiandrogen cyproterone acetate on sperm count morphology motility and cervical mucus penetration. 5-10 mg/day failed to decrease sperm penetration in vitro and 2 pregnancies occurred in 7 volunteers. Side effects included depressive mood changes in 2 men and dizziness and weakness in another. Study 5 a 12-month clinical trial evaluated 500 mcg/day of levonorgestrel and 200 mg testosterone enanthate monthly since this combination emerged as the most promising in terms of sperm count motility and side effects. Severe oligospermia was noted in 5 of 13 volunteers and 7 showed extensive decreases in sperm counts. No consistent changes were seen in platelet aggregability or fibrinolytic activity and capacity. The breakthrough in sperm counts noted in 2 volunteers after 12-13 months of successful suppression of spermatogenesis indicates that azoospermia is an absolute requirement for a male contraceptive which acts by suppressing spermatogenesis. It is recommended that increased doses of oral levonorgestrel and low oral doses of a testosterone ester be evaluated in future studies. (summary in DAN)