Natural and synthetic estrogen
Estrogens that treat endocrine
system disorders include:
• natural products, such as conjugated estrogenic
substances, estradiol, and estropipate
• synthetic estrogens, such as esterified
estrogens,estradiol cypionate, estradiol valerate, and ethinylestradiol.
Estrogens are well absorbed and distributed
throughout the body. Metabolism occurs in the liver, and the metabolites are excreted
primarily by the kidneys.
The exact mechanism of action of estrogen isn’t
clearly under-stood, but it’s believed to increase synthesis of
deoxyribonucleic acid, ribonucleic acid, and protein in estrogen-responsive
tissues in the female breast, urinary tract, and genital organs.
Estrogens are prescribed:
primarily for hormone replacement therapy in postmenopausal women to
relieve symptoms caused by loss of ovarian function (see Hormone replacement therapy and heart disease)
less commonly for hormonal replacement therapy in women with primary
ovarian failure or female hypogonadism (reduced hormonal secretion by the
ovaries), for prevention and treatment of osteoporosis in postmenopausal women,
and in patients who have undergone surgical castration
palliatively to treat advanced, inoperable breast cancer in
post-menopausal women and prostate cancer in men.
Relatively few drugs interact with estrogens:
§ Estrogens may decrease the effects of anticoagulants,
increas-ing the risk of blood clots.
§ Antibiotics, barbiturates, carbamazepine,
phenytoin, primidone, and rifampin reduce estrogen effectiveness.
§ Estrogens interfere with the absorption of
dietary folic acid, which may result in a folic acid deficiency. (See Adverse reactionsto estrogens.)