Name: Conjugated estrogens (Premarin)
Class: Estrogen
Mechanism: Diffuses across cell membranes and binds to cytoplasmic receptor proteins. Complex enters nucleus and interacts w/DNA to initiate RNA synthesis. Stimulates development of the endometrial lining, maintains normal structure of skin and blood vessels in E, antagonizes PTH effects on bone, reduces motility of the bowel, enhances coagulability of blood, increases HDL, decreases LDL.
Absorption:
Dist.: Metabolism.: Excretion, t½:
Toxicity/S.E.s: Increased risk of breast and endometrial cancer.
Utility: Postmenopausal estrogen replacement therapy to treat hot flashes, atrophic vaginitis, and urethral changes, and to prevent osteoporosis and cardiovascular disease.
Special Features: Usu. combined with a progestin to reduce the risk of endometrial carcinoma. Only useful prophylactically for osteoporosis. Less first-pass Metabolism. than estradiol ® more effective oral administration.