Gynprogest Mechanism of Action

Pharmacotherapeutic group: Genito-urinary system and sex hormones. ATC Code: G03DA04.
Pharmacology: Pharmacodynamics: Progesterone is a natural progesterone, the main hormone of the corpus luteum and the placenta. It acts on the endometrium by converting the proliferating phase to the secretory phase. Gynprogest capsules have all the properties of endogenous progesterone with induction of a full secretory endometrium and in particular gestagenic, antiestrogenic, slightly anti- androgenic and antialdosterone effects.
Pharmacokinetics: Absorption: Micronised progesterone is absorbed by the digestive tract. Pharmacokinetic studies conducted in healthy volunteers have shown that oral administration of 2 capsules (200 mg), plasma progesterone levels increased to reach the Cmax of 13.8 ng/ml +/- 2.9 ng/ml in 2.2 +/-1.4 hours. The elimination half-life observed was 16.8 +/-2.3 hours. Although there were inter-individual variations, the individual pharmacokinetic characteristics were maintained over several months, indicating predictable responses to the drug.
Distribution: Progesterone is approximately 96%-99% bound to serum proteins, primarily to serum albumin (50%-54%) and transcortin (43%-48%).
Elimination: Urinary elimination is observed for 95% in the form of glycuroconjugated metabolites, mainly 3a, 5 B-pregnanediol (pregnanediol).
Metabolism: Progesterone is metabolised primarily by the liver. The main plasma metabolites are 20 a hydroxy-4a-prenolone and 5 a-dihydroprogesterone. Some progesterone metabolites are excreted in the bile and these may be deconjugated and further metabolized in the gut via reduction, dehydroxylation and epimerization. The main plasma and urinary metabolites are similar to those found during the physiological secretion of the corpus luteum.