Prempro Lawsuits
By Aaron Larson
March, 2005
Contents
What is Prempro
Prempro (conjugated estrogen and medroxyprogesterone) is manufactured by Wyeth Ayerst, as a hormone replacement medication for post-menopausal women.
Factual Background
The use of hormone replacement therapy (HRT) is common with post-menopausal women. The goal of HRT is to moderate the symptoms of menopause, and ideally to minimize the health consequences such as osteoporosis which are associated with reduced hormone levels.
In 1991, the National Heart, Lung, and Blood Institute (NHLBI) and units of the National Institutes of Health sponsored The Women's Health Initiative (WHI). The focus of the WHI was on finding ways to prevent heart disease, osteoporosis, breast cancer, and colorectal cancer. The WHI's studies included 161,000 healthy post-menopausal women.
One of the WHI's clinical studies involved 16,608 post-menopausal women with a uterus. These women were given either estrogen plus progestin in the form of the medication Prempro, or a placebo. By July, 2002, after little more than five years of study, this trial was terminated when the NHLBI determined that the risks of the therapy outweighed its benefits. The study found a significant increase in the incidence of abnormal mammograms, and also in the incidence and severity of breast cancer, among women who were taking Prempro as compared to the women in the placebo group. There was also concern of increased risk of pulmonary embolism, heart attack, and stroke.
Wyeth's press releases on the safety of Prempro suggest that its warning labels are adequate and that the proper and appropriate use of Prempro for hormone replacement therapy is both safe and effective.
Prempro Litigation
A number of law firms are actively recruiting potential clients who have taken Prempro, and at least one class action lawsuit has been filed against Wyeth. These law firms believe that even though Prempro can provide legitimate medical benefits, the risks associated with its use render it inherently unsafe.
At the same time, there is significant difference of opinion as to whether there is sufficient evidence of causation to support successful litigation. In other words, it is not clear that the law firms will be able to establish that Prempro is the actual cause of the medical conditions reported in the study, or of similar medical conditions in any given patient. It is expected that any litigation over Prempro will be complex, fiercely defended, and difficult for the plaintiffs to win.