ATC Group: G03C Estrogens

Diethylstilbestrol is a synthetic nonsteroidal estrogen, that was widely used to prevent potential miscarriages by stimulating the synthsis of estrogen and progesterone in the placenta. It was also used for the treatment of symptoms arising during menopause and following ovariectomy and for senile vaginitis and vulvar dystrophy. Diethylstilbestrol was used as a postcoital emergency contraceptive (morning-after pill). It has also been used for the prevention of postpartum breast engorgement, for dysfuctional menstrual cycles and for the treatment of female hypogonadism. Diethylstilbestrol is now rarely used to treat prostate cancer and occacionally in postmenopausal women with breast cancer because of its side-effects.

Estradiol, is chemically and biologically identical to endogenous human estradiol. It substitutes for the loss of oestrogen production in menopausal women, and alleviates menopausal symptoms. Oestrogens prevent bone loss following menopause or ovariectomy.

Estriol is a steroid, a weak estrogen, specifically an agonist of the estrogen receptors ERα and ERβ. It is one of three major endogenous estrogens, the others being estradiol and estrone.

The active ingredients of conjugated estrogens are primarily the sulfate esters of estrone, equilin sulfates, 17α-estradiol and 17β-estradiol. These substitute for the loss of estrogen production in menopausal women, and alleviate menopausal symptoms. Estrogens prevent bone loss following menopause or ovariectomy.

Estrone is an aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone. Estrone is a major mammalian estrogen. It is converted from androstenedione directly, or from testosterone via estradiol. It is produced primarily in the ovaries, placenta, and in peripheral tissues (especially adipose tissue) through conversion of adrostenedione.

Ethinylestradiol is chemically and biologically identical to endogenous human oestradiol. It substitutes for the loss of estrogen production in menopausal women, and alleviates menopausal symptoms. Estrogens prevent bone loss following menopause or ovariectomy.

Tibolone is rapidly metabolised into three compounds, which all contribute to the pharmacodynamic profile of tibolone. Two of the metabolites (3α-OH-tibolone and 3β-OH-tibolone) have oestrogenic-like activities, whereas the third metabolite (4Δ-isomer of tibolone) has progestogenic and androgenic-like activities.