PREMARIN

Absorption

Estropipate is well absorbed through the skin and gastrointestinal tract. When applied for a local action, absorption is usually sufficient to cause systemic effects.

The Uses of PREMARIN

Estrone Sulfate is a precursor of estrogen and is a circulating steroid found in men, non-pregnant women, and post-menopausal women.

Background

Estrone sulfate (as estropipate) is a form of estrogen. It has several uses such as: alleviate symptoms of menopause as hormone replacement therapy, treatment some types of infertility, treatment of some conditions leading to underdevelopment of female sexual characteristics, treatment of vaginal atrophy, treatment of some types of breast cancer (particularly in men and postmenopausal women), treatment of prostate cancer and prevention of osteoporosis.

Indications

Estropipate is used for the treatment of moderate to severe vasomotor symptoms associated with the monopause, and moderate to severe symptoms of vulval and vaginal atrophy associated with the menopause. It is also used to treat hypoestrogenism due to hypogonadism, castration or primary ovarian failure, and prevent postmenopausal osteoporosis.

Definition

ChEBI: A steroid sulfate that is the 3-sulfate of estrone.

Pharmacokinetics

Estropipate is an estrogenic substance. It acts as naturally produced estrogen does. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.

Metabolism

Exogenous estrogens are metabolized in the same manner as endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium of metabolic interconversions. These transformations take place mainly in the liver. Estradiol is converted reversibly to estrone, and both can be converted to estriol, which is the major urinary metabolite. Estrogens also undergo enterohepatic recirculation via sulfate and glucuronide conjugation in the liver, biliary secretion of conjugates into the intestine, and hydrolysis in the gut followed by reabsorption. In postmenopausal women, a significant proportion of the circulating estrogens exist as sulfate conjugates, especially estrone sulfate, which serves as a circulating reservoir for the formation of more active estrogens.