Conversion of tibolone to 7&agr;-methyl-ethinyl estradiol using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry: interpretation and clinical implications

@article{Zacharia2006ConversionOT,
  title={Conversion of tibolone to 7\&agr;-methyl-ethinyl estradiol using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry: interpretation and clinical implications},
  author={L. Zacharia and E. Jackson and H. Kloosterboer and B. Imthurn and R. Dubey},
  journal={Menopause},
  year={2006},
  volume={13},
  pages={926-934}
}
Objective: Tibolone, a hormone therapy drug, is used to treat climacteric symptoms. This drug is rapidly metabolized into three major metabolites (3&agr;-hydroxytibolone, 3&bgr;-hydroxytibolone, and &Dgr;4-tibolone). One clinical study provided evidence of conversion of tibolone to another estrogenic metabolite, 7&agr;-methyl-ethinyl estradiol (MEE). However, no evidence of MEE formation was found in another study using the human aromatase enzyme. Because MEE was analyzed by gas chromatography… Expand
7&agr;-Methyl-ethinyl estradiol is not a metabolite of tibolone but a chemical stress artifact
TLDR
7&agr;-MEE is not a metabolite of tibolone but is a chemical artifact generated during analytical procedures with derivatization, and cannot be demonstrated in plasma from postmenopausal women after single or multiple doses of tIBolone. Expand
Can 19-nortestosterone derivatives be aromatized in the liver of adult humans? Are there clinical implications?
  • H. Kuhl, I. Wiegratz
  • Medicine
  • Climacteric : the journal of the International Menopause Society
  • 2007
TLDR
19-nortestosterone derivatives (norethisterone, norethynodrel, tibolone) can readily be aromatized in the adult human liver, which leads to the formation of the potent estrogens ethinylestradiol from norehisterone or nore fourthodrel and 7α-methyl-ethinylest radiol from tibiaolone. Expand
Application of UPLC–MS/MS for separation and quantification of 3α-Hydroxy Tibolone and comparative bioavailability of two Tibolone formulations in healthy volunteers
TLDR
It is concluded that test formulation of Tibolone is bioequivalent to reference formulation of TsI, and this method was successfully applied to a pharmacokinetic study in 50 post-menopausal/surgical menopause female human volunteers under fasting conditions. Expand
The other side of progestins: effects in the brain.
TLDR
The role exerted by different progestins, currently used for contraception or in postmenopausal hormone replacement therapies, in regulating cognitive functions as well as social behavior and mood is reported. Expand
[Effect of tibolone on endometrium of castrated rats].
TLDR
High doses of tibolone, given for long periods of time to castrated female rats, have an estrogenic effect which can be dose-dependent, causing proliferation in the endometrium and causing changes in the cell differentiation (squamous metaplasia), but do not lead to hyperplasia. Expand

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TLDR
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