Desogestrel, a New Progestational Compound: A Comparative Study with Lynestrenol, Performed in Ovariectomized Women

Abstract

A new progestational compound, desogestrel, was given orally to four otherwise healthy, ovariectomized volunteers who had first been treated for two cycles with ethinylestradiol and lynestrenol (given sequentially) and then primed with ethinylestradiol. The effects of decreasing doses of desogestrel (250 to 15 μg) in combination with 50 μg ethinylestradiol were compared with those of 1 mg lynestrenol plus 50 μg ethinylestradiol. Variables studied were basal body temperature, vaginal cytology (karyopyknotic index), cervical mucus (including Spinnbarkeit and ferning) and endometrial biopsies. In addition, body weight, blood pressure and selected biochemical variables were monitored. No side effects attributable to the treatment were noted. Progestational effects were observed on all variables in volunteers with adequate priming. Basal body temperature rose in all volunteers on desogestrel at doses down to 60 μg to the same extent as those with I mg lynestrenol. The karyopyknotic index did not react to estrogen priming in 2 volunteers, and the results with the 2 other volunteers were inconclusive. Cervical mucus became thick and scanty with reduced Spinnbarkeit at doses of desogestrel down to 60 μg as well as with 1 mg lynestrenol. Crystallization of mucus (ferning) ceased at a dose of 30 pg desogestrel and endometrial biopsies showed marked secretion at doses of desogestrel down to 30 μg; 60 μg was considered to be equipotent to 1 mg lynestrenol. The ovariectomized woman with her uterus intact appears to be a good model for the initial testing of progestational compounds.