Clinical studies with an antigonadotropin--Danazol.
Laboratory and clinical evaluation of Danazol, a synthetic (2,3-isoxozol) derivative of 17-alpha-ethinyl-testosterone, is discussed. Danazol was administered to 8 volunteers for control studies and to 62 patients for a variety of gynecologic and endocrine disorders, in oral doses of 800 mg/day in adults and 200-400 mg/day in children for a period of 21 to 240 days. Oral administration of Danazol, to humans, displayed a profound inhibitory effect on gonadal function. In females, estrogenic activity was abolished or considerably reduced and there was no evidence of ovulation. The midcycle, ovulatory surge of LH and FSH failed to occur during treatment. In 2 patients with elevated total urinary gonadotropins, the titers were lowered while on medication. The effects of Danazol were reversible and confined to treatment period. In addition to antigonadotropic properties, Danazol demonstrated some androgenicity, especially in patients already displaying such tendencies. Long term weight gain was noted in about 40 percent of cases, and considered an expression of anabolic action. No estrogenic, progestational or antiprogestational effects were observed. Clinical finding are essentially in agreement with results of animal experiments. A discrepency is noted as to progestational-like effect. In animals pre-treated with estrogen, injections of Danazol produced a progestational-like change in the endometrium. No such effect was observed in humans. The difference may be due to the different route of administration. Danazol was administered for therapeutic purposes to patients in whom amenorrhea, suppression of gonadal steroids, or inhibition of pituitary gonadotropins was expected to be beneficial. The clinical application of Danazol appears to be of particular advantage in cases of precocious puberty, endometriosis, virginal breast hypertrophy and chronic cystic mastitis.