Estrogen therapy may cause a 2-4 fold increased risk of gallbladder disease requiring surgery. Estrogens should never be administered to a pregnant female or immediately postpartum due to risk of congenital lesions with malignant potential. Drug may be excreted in human milk. Estrogens decrease both quantity and quality of milk. Use only when clearly necessary.
Estrogens promote growth and development of the vagina, uterus, fallopian tubes and breasts.
Transdermal estradiol absorption is greatest when applied to the hip and buttocks compared to lower abdomen, however all 3 sites are acceptable. Transdermal estrogen is minimally metabolized by the skin so that therapeutic serum levels of estradiol are obtained with lower circulating levels of estrone and estrone conjugates, thus requiring lower total doses. Transdermal administration produces mean serum estradiol concentrations comparable to oral estrogen concentrations at about 20 times the transdermal doses. Estradiol is primarily eliminated by liver metabolism. A new patch should be applied twice per week or every three to four days.