Tibolone is a synthetic steroid with estrogenic effects on brain, vagina, and bone without stimulating the endometrium. During tibolone treatment, it is thought that the progestagenic properties of tibolone stimulate cell differentiation, which effectively counterbalances the growth-stimulating effects of the estrogenic properties of tibolone. The objective of this study was to characterize the...

Sulfation is a major pathway in humans for the biotransformation of steroid hormones and structurally related therapeutic agents. Tibolone is a synthetic steroid used for the treatment for climacteric symptoms and postmenopausal osteoporosis. Sulfation inactivates the hydroxylated metabolites, 3alpha-hydroxytibolone (3alpha-OH-tibolone) and 3beta-hydroxytibolone (3beta-OH-tibolone), and contrib...

An international multidisciplinary panel of experts in the management of the menopause met at the 4th Amsterdam Menopause Symposium in October 2004 to determine the specific place of tibolone, a synthetic steroid with a unique clinical profile, within the wide range of currently available postmenopausal therapy options. The consensus was that tibolone is a valuable treatment option for women wi...

OBJECTIVE To investigate the efficacy and safety of remifemin (isopropanolic extract of cimicifuga racemosa) treating perimenopausal symptoms in comparison of tibolone. METHODS One hundred and eighty postmenopausal women at range of 40 - 60 years old were enrolled in a multicenter, randomized and double blind study. They were divided into remifemin and tibolone group at ratio 1:1. The therape...

A novel, fast, sensitive and robust method based on ultra-performance liquid chromatography coupled to atmospheric pressure electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) has been developed to separate two Tibolone stereoisomers i.e., 3α-Hydroxy Tibolone and 3β-Hydroxy Tibolone and to quantify 3α-Hydroxy Tibolone using p-toulenesulfonyl isocyanate (PTSI) as a derivatizing rea...

Estrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones would be clinically advantageous. However, data from the Million Women Study suggests that Tibolon...

Levels of nonsulfated and sulfated tibolone metabolites were determined in plasma, urine, and feces from six ovariectomized, mature female cynomolgus monkeys after a single dose and multiple p.o. doses (including bile) of tibolone using validated gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry assays. In plasma, the predominant nonsulfated metabolite afte...

Tibolone is a selective tissue estrogenic activity regulator (STEAR). In postmenopausal women, it acts as an estrogen on brain, vagina, and bone, but not on endometrium and breast. Despite ample supporting in vitro data for tissue-selective actions, confirmative tissue levels of tibolone metabolites are not available. Therefore, we analyzed tibolone and metabolites in plasma and tissues from si...

OBJECTIVE The objective was to compare the effects of tibolone and hormone therapy (HT) on lipid profile, vasodilation, and factors associated with inflammation and hemostasis. METHODS AND RESULTS Fifty-three women received micronized progesterone (MP, 100 mg) with conjugated equine estrogen (CEE, 0.625 mg) or tibolone (2.5 mg) daily for 2 months, with a 2-month washout period. Compared with ...

In vivo metabolism of tibolone was studied in three healthy postmenopausal volunteers after daily oral administration of 2.5 mg of tibolone for 5 days and a single dose of 2.5 mg approximately equal 555 kBq of [(14)C]tibolone on day 6. The 0- to 192-h recovery of radioactivity in urine and feces was 31.2 +/- 10.5 and 53.7 +/- 5.1%, respectively. Total 0- to 192-h recovery ranged from 78.5 to 94...