title: Pharmacokinetics of natural progesterone administered in the form of a vaginal tablet.
abstract: Our study was conducted to assess the pharmacokinetics of natural progesterone administered in the novel formula of an effervescent vaginal tablet. Fifty post-menopausal women, with a median age of 43.5 years (range 28-55), volunteered to participate in the research. All women discontinued their hormonal replacement therapy 1 month prior to the study. The pharmacokinetics of 50 and 100 mg of progesterone administered as a vaginal tablet were evaluated. After the initial administration of 50 mg or 100 mg, a mean serum Cmax of 20.43 +/- 8.01 nmol/l and 31.61 +/- 12.62 nmol/l (P < 0.0004) was reached at a Tmax of 6.1 +/- 2.63 and 6.4 +/- 3.35 h respectively. The terminal half-life was 13.18 +/- 1.3 and 13.7 +/- 1.05 h respectively. Continuous use of the 100-mg tablet resulted in a mean serum progesterone concentration of 26.08 +/- 13.96 nmol/l and 21.42 +/- 16.32 nmol/l after 14 and 30 days respectively. Women >40 years were found to have a significantly lower Tmax compared to younger women (P = 0.02). The continuous use of vaginal progesterone did not influence the hormonal, liver or lipid profiles evaluated. Only three (6%) women suffered from mild vaginal irritation. Natural progesterone given as a vaginal tablet is well tolerated, safe and an easily administered treatment. Even in a non-oestrogenized vagina the absorption was efficient and the 100 mg dosage resulted in adequate serum progesterone concentrations.
authors.affiliation: Department of Obstetrics and Gynecology, Rabin Medical Center, Petah Tikva, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Levy
authors.forename: S
authors.initials: S
authors.lastname: Gurevitch
authors.forename: I
authors.initials: I
authors.lastname: Bar-Hava
authors.forename: J
authors.initials: J
authors.lastname: Ashkenazi
authors.forename: A
authors.initials: A
authors.lastname: Magazanik
authors.forename: R
authors.initials: R
authors.lastname: Homburg
authors.forename: R
authors.initials: R
authors.lastname: Orvieto
authors.forename: Z
authors.initials: Z
authors.lastname: Ben-Rafael
mesh_terms: D000042:Absorption; D000282:Administration, Intravaginal; D000328:Adult; D015992:Body Mass Index; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D017698:Postmenopause; D011374:Progesterone / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics*; D013607:Tablets
chemical_list: D013607:Tablets; D011374:Progesterone