Hormone Replacement Therapy Stroke Risk. Taking hormone replacements made by companies including Wyeth and Schering AG raises the risk of a stroke by 29 percent, according to a review of clinical trials published in the British Medical Journal.
Hormone replacement therapy increases the severity of a stroke and, in particular, boosts the risk of ischemic stroke, which is caused by an insufficient blood supply to the brain, researchers at the University of Nottingham, England, said on the journal’s Web site, citing 28 trials involving 39,769 patients.
“Patients at high risk of stroke such as those with previous stroke, coronary heart disease or multiple vascular risk factors should stop taking HRT unless there’s a strong contrary medical reason,” said lead researcher Philip Bath, a professor of stroke medicine at University of Nottingham.
This analysis adds to research that already curbed a once- common practice of keeping women on hormone therapies for years after menopause to protect their bones against fracture. The U.S. National Institutes of Health said in July 2002 that taking estrogen or a combination of estrogen and progesterone may raise the risk of heart disease.
It is known that hormone treatments raise the risk of stroke
“It is known that hormone treatments raise the risk of stroke,” said Schering spokeswoman Astrid Forster in an interview without having seen the analysis. “The risks are clearly listed in the instructions for use.” Schering has said in the past that it was aware of the risk.
In Europe, the acceptance rate of HRT products for menopausal women is about 10 percent, from 15 percent, according to market research by Schering. In Northern Europe the rate is about 18 percent, the same as in the U.S. where it used to be 40 percent before the NIH research, Schering said.
About 8.5 million women in the U.S. take hormone drugs, such as Wyeth’s Premarin and Prempro, compared with about 15 million before research linked the medicines to heart disease and cancer, Wyeth has said. The U.S. Food and Drug Administration added warnings to hormone drugs in 2002.
“The risk of stroke is currently in our label,” said Ginger Constantine, Wyeth’s vice president of women’s health and bone-repair clinical research in a telephone interview without having seen the analysis. “There have been some studies, which have shown a slight increased risk. There are some clinical trials that showed no increased risk.”
Researchers haven’t deciphered why HRT increases stroke and its severity when some studies have suggested it may have a protective effect, Bath said. Doctors used to say HRT may protect the heart and brain during aging, in addition to their proven benefit in protecting bones against fractures. That led many women to take hormone treatment for decades after menopause ended.
“Given the findings, hormone replacement therapy cannot be recommended for primary or secondary prevention of stroke,” Bath said in an e-mailed release.
Makers of hormone replacement products include Schering, Wyeth, King Pharmaceuticals Inc., Pfizer Inc., Teva Pharmaceutical Industries Ltd. and Novartis AG.