title: Studies of the kinetics and metabolism of 17 beta-heptanoyl-17 alpha-ethinyl-4-oestren-3-one-7-3H (norethisterone enanthate) in humans following intramuscular injection.
abstract: The kinetics and metabolism of 17 beta-heptanoyl-17 alpha-ethinyl-4-oestren-3-one-7-3H (7-3H-norethisterone enanthate, NET-En) after i.m. injection in two female subjects is described. 177.4 mg and 174.5 mg NET-En were injected. Maximum 3H-activity in plasma was reached 8 to 14 days after the injection. In terms of NET-En it amounted to 70-100 mug/100 ml. Maximum NET concentration was reached on the 4th to 8th day and amounted to about 1 mug/100 ml. After 4 weeks NET concentration was still about 0.05 to 0.1 mug/100 ml and even after 6 weeks NET was still detectable in plasma. In 14 days the two subjects excreted about 13% of the administered dose in the urine and about 15% and 21%, respectively, in the faeces. On the basis of a rough calculation, the subjects eliminated about 60% and 55% of the radioactivity with urine and faeces within 42 days.
mesh_terms: D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D007700:Kinetics; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism; D013997:Time Factors
chemical_list: D009640:Norethindrone