Pharmacokinetics of ethynyloestradiol in women for different populations.
The pharmacokinetics of a dose of 50 microgram ethynyloestradiol administered orally was studied in fourteen centres. Absorption was rapid and the highest serum concentrations of total ethynyloestradiol were found in most subjects at 1 h and by 24 h concentrations were less than 250 pg/ml. Calculation of the half-lives for absorption, distribution and elimination showed wide variations between subjects, the half-life of elimination varying from 2.5 h to more than 30 h. Bioavailability as measured by the area under the serum ethynyloestradiol concentration-time curve also showed more than a ten-fold variation. Intra-centre differences in the various parameters measured were as large as the inter-centre differences.
D001682:Biological Availability; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D009640:Norethindrone / Q000008:administration & dosage
D004997:Ethinyl Estradiol; D009640:Norethindrone