Estrogen replacement therapy and the estraderm transdermal system

One reliable, controlled and convenient method of delivering parenteral estrogen replacement therapy is by means of a transdermal patch known as the Estraderm Transdermal System, which contains a 17-beta estradiol formulation. The primary side effect appears to be a localized skin irritation in about 15 percent of the women using this route. Most women find this irritation annoying but not enough to necessitate stopping therapy. Studies indicate that the patch provides amelioration of climacteric symptoms that is comparable to the oral estrogens. Preliminary research shows that parenteral estrogen is as effective as oral estrogen in decreasing the risk of osteoporosis. No adverse changes in lipid-lipoprotein levels have been found. A recent Swedish study found an increased relative risk of breast cancer with estradiol and with combined estrogen-progestin use for postmenopausal therapy. Thus, more research on the long-term hormonal replacement effects of the patch is indicated. One advantage of the transdermal delivery system is a first bypass of the liver, thus decreasing the possible risk of renin substrate elevation and the potential increase in blood pressure associated with oral estrogen therapy.