The top-selling drug in America is Premarin, a combination of estrogens refined from pregnant mares' urine. This formulation has been on the market for more than 50 years. Few drugs have experienced such phenomenal success for such a long time.
Initially, Premarin was prescribed to relieve hot flashes and other symptoms of menopause. In the 1960s and early 1970s this drug became extremely popular. Many women were led to believe that hormones could keep them looking young indefinitely. The book "Feminine Forever" endorsed estrogen replacement therapy.
When reports surfaced that estrogen therapy dramatically increased the risk of uterine cancer, sales plummeted. Premarin lost much of its allure.
In the 1980s, however, physicians started prescribing a combination of Premarin and Provera, a progestin-type hormone that counteracts the impact of estrogen on uterine tissue.
Additional research demonstrated that Premarin could help prevent bone loss and fractures after menopause. Estrogen also appears to lower the risk of heart disease, a serious concern as women age. Such studies propelled Premarin back into the No. 1 slot of prescription popularity.
Despite this success a lingering question remained on the horizon. Did estrogen replacement therapy (ERT) increase a woman's risk of breast cancer? Women have been concerned and confused by this dilemma.
Until recently, researchers have disagreed about the level of risk. Most information was based on old data from women who took estrogen alone. Many physicians argued that adding progesterone would eliminate the risk of breast cancer seen with pure estrogen.
But now a major new study involving more than 100,000 nurses confirms that estrogen replacement therapy significantly increases the risk of breast cancer in postmenopausal women and demonstrates that progesterone does not diminish this risk.
The Harvard scientists conclude: "The substantial increase in the risk of breast cancer among older women who take hormones suggests that the trade-offs between risks and benefits should be carefully assessed."
For many women, estrogen replacement therapy is still the best option for overall health. The family and health history of each individual must be considered when the decision is made whether or not to undertake long-term hormone treatment.
It has taken more than 50 years to answer the breast cancer question. More research is desperately needed to determine the total health effects of this popular regimen. In light of the new findings, however, physicians should discuss with their patients both the risks as well as the benefits of estrogen therapy.
Q: I have high blood pressure for which I must take Cardura. This has been more difficult to manage ever since I started on Estrace. Can hormones contribute to keeping blood pressure high?
A: Elevated blood pressure may result from estrogen. If your blood pressure is difficult to control, perhaps you and your physician should re-evaluate the dose of your hormone therapy.
Joe Graedon is a pharmacologist. Teresa Graedon hold a Ph.D. in medical anthropology and is a nutrition expert. The People's Pharmacy with Joe and Terry Graedon is a call-in show syndicated to many public radio stations.