Serum concentrations of ethinylestradiol, 3-keto-desogestrel, SHBG, CBG and gonadotropins during treatment with a biphasic oral contraceptive containing desogestrel.
During a cross-over study, the pharmacokinetics of ethinylestradiol (EE) and 3-keto-desogestrel (KDG) were investigated on days 7 and 22 of one cycle of treatment with two biphasic formulations containing 50 micrograms EE (7 tablets) and 50 micrograms EE + 125 micrograms desogestrel (DG) (15 tablets) (50/50 EE) or 40 micrograms EE + 25 micrograms DG (7 tablets) and 30 micrograms EE + 125 micrograms DG (15 tablets) (40/30 EE). Peak serum levels and areas under the curve of EE increased significantly by 50% between days 7 and 22 of those taking 50/50 EE, while during treatment with 40/30 EE, no difference was found between days 7 and 22. Both formulations caused identical KDG levels on day 22. There were only slight differences in the effects of both preparations on sex-hormone-binding globulin (SHBG; +150 to +160%) and on corticosteroid-binding globulin (CBG; +130 to +150%) on day 7. On day 22, the changes were more pronounced with 50/50 EE (SHBG, +310%; CBG, +240%) than with 40/30 EE (SHBG, +250%; CBG, +180%). On day 22 after discontinuation of treatment, the SHBG and CBG levels were still significantly above the control values. Using both formulations, LH and FSH levels were significantly suppressed on day 22, while on day 7 no significant reduction was observed. The rise in the EE levels between days 7 and 22 of 50/50 EE intake and the time course of the EE concentrations during treatment with 40/30 EE appear to be due to an inhibition of hepatic metabolism by the contraceptive steroids, as EE is nearly exclusively bound to albumin which does not change.
Jung-Hoffmann
C
C
Department of Obstetrics and Gynecology, Johann Goethe University, Frankfurt am Main, FRG.
Storch
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A
Kuhl
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H
D000328:Adult; D003278:Contraceptives, Oral, Hormonal / Q000493:pharmacokinetics* / Q000494:pharmacology; D017135:Desogestrel / Q000097:blood / Q000493:pharmacokinetics*; D004997:Ethinyl Estradiol / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007700:Kinetics; D007986:Luteinizing Hormone / Q000097:blood; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D014156:Transcortin / Q000378:metabolism*
D003278:Contraceptives, Oral, Hormonal; D012738:Sex Hormone-Binding Globulin; C044815:etonogestrel; D004997:Ethinyl Estradiol; D017135:Desogestrel; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D014156:Transcortin