In Vivo Formation of Ethinylestradiol After Intramuscular Administration of Norethisterone Enantate

  title={In Vivo Formation of Ethinylestradiol After Intramuscular Administration of Norethisterone Enantate},
  author={Christian Friedrich and Matthias Berse and Stefan Klein and Beate Rohde and Joachim H{\"o}chel},
  journal={The Journal of Clinical Pharmacology},
It is known that a small fraction of orally administered norethisterone is metabolically converted to ethinylestradiol. This exploratory, open‐label, nonrandomized study was conducted to investigate the systemic exposure to ethinylestradiol after intramuscular administration of norethisterone enantate in comparison with the exposure to ethinylestradiol after administration of a standard combined oral contraceptive. Sixteen healthy premenopausal women received an oral contraceptive… Expand
Pharmacokinetics, metabolism and serum concentrations of progestins used in contraception.
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Analytical Method Validation of RP-HPLC Method for Simultaneous Estimation of Levonorgestrel and Ethinylestradiol from Combined DrugProduct
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In vivo conversion of norethisterone and norethisterone acetate to ethinyl etradiol in postmenopausal women.
It is concluded that at therapeutic doses of the progestogens, the exposure to metabolically derived ethinyl estradiol is probably of little clinical significance not only in fertile women using oral contraceptive combination preparations containing norethisterone and ethinyl Estradiol, but also in postmenopausal women who receive oral doses of estradio for estrogen replacement. Expand
Formation of ethinylestradiol in postmenopausal women during continuous treatment with a combination of estradiol, estriol and norethisterone acetate.
Investigation of the serum concentrations of estradiol, ethinylestradiol and norethisterone in 25 patients of a gynecological practice who were continuously treated for climacteric complaints concluded that in the presence of the highEstradiol concentrations the low conversion rate of norehisterone into ethinylstradiol is probably without clinical significance. Expand
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Metabolism of levonorgestrel, norethindrone, and structurally related contraceptive steroids.
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In vivo conversion of norethisterone to ethynyloestradiol in perimenopausal women
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In vivo conversion of norethisterone to ethynyloestradiol in Friedrich et al 789 perimenopausal women
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  • Guidance for industry: Bioanalytical method validation. Drugs/Guidances/ucm070107.pdf. Accessed November 20,
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Guidance for industry: Bioanalytical method validation