Estrogen and progestin drugs

Estrogen drugs can be divided into three types:
1. Natural Estrogen: the natural estrogen secreted by the body includes estradiol, estrone and estriol. At present, the estrogen commonly used in clinical contains its derivatives, estradiol and its synthetic derivatives, such as the ong-acting estrogen estradiol benzoate, estradiol valerate, estradiol cypionate used for injection and the orally active ethinyl estradiol, quinestrol. And they are all the commonly used clinical estrogen drugs, which can also be combined with progestogen to form various compounds and be used for contraceptives. The estriol has weaker estrogenic activity than estradiol, and is characterized by the selection to vagina and cervical canal. The estriol in clinic is mainly used to cure menopausal syndrome and senile vaginitis. Their metabolic processes in the body is similar to the natural estrogen. Premarin is a kind of natural conjugated estrogens, and can be used as a supplement therapeutic agent for estrogen.
2. Semi-synthetic estrogen: ethinyl estradiol is a oral potent estrogen, and the effect of ethinyl estradiol is about 20 times than that of diethylstilbestrol. Its long derivatives is nilestriol.
3. The synthetic estrogen (non-steroidal estrogens): the nonsteroidal synthetic estrogen diethylstilbestrol and other drugs are also commonly used in the clinical practice, in which the chloroallyl female ether is the best variety.

The progesterone drugs generally include the progesterone and the drugs that have similar physiological activity with the natural progesterone (progestogens). Its physiological effects are closely related with the progesterone. It changes the uterine tissue in order to facilitate the transport implantation and development of the fertilized egg. At the same time,   it can suppress the ovulation and effect the function of the uterus and the development of the mammary gland. The natural progesterone comes from the cyclical secretion of the corpus luteum and can be synthesized with Yaro sapogenin and sterol in industry.
The engineered progestin compounds, according to their chemical structure, can be divided into two categories:
1. progesterone derivatives 17α- hydroxyprogesterone class, such as medroxyprogesterone acetate (medroxyprogesterone acetate, medr-oxyprogesterone acetate), megestrol acetate, chlormadinone (chlormadinone acetate) and injectable long-acting progesterone caproate (17α- hydroxyprogesterone caproate, hydroxyprogester-one caproate) and the like.
2. 19-nortestosterone class, such as norethindrone, norethindrone (norethynodrel), and other high-quinolone represented. Their structure is based on the 19-acetylene testosterone that has different structure with the progesterone and the position of the methyl-10,13-substituted have also been changed.

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