Two Canadian women have died and numerous others have suffered blood clots, heart attacks and other medical problems in the span of about four years after using the well-known but increasingly controversial Evra birth-control patch, according to a Health Canada report.
Although medical research has not concluded there is a direct relationship between the Evra patch and reported problems, concerns have been great enough to raise questions about the product's safety and prompt government health officials to issue warnings in Canada and the United States.
Advocacy groups have also sounded the alarm, with some saying the product should not be on the market.
"[Women] shouldn't use it. It shouldn't be used because it's a new product with no unique advantage," said Sidney Wolfe, director of the health research group at Public Citizen, a U.S.-based consumer group founded by Ralph Nader.
The Evra transdermal system is a prescription-only adhesive patch that delivers hormones to a woman's body through the skin.
Women using the product apply a new patch each week for three consecutive weeks, followed by one patch-free week.
It has been available in Canada since 2004, and in that time Health Canada has received 93 reports of adverse reactions, the majority of which involved women in their teens, 20s or early 30s.
While many of the reports were for mild reactions such as dizziness or nausea, the department received 17 reports of cases involving blood clots and heart attacks.
Janssen-Ortho issued a statement defending the safety of the patch, adding that all hormone-based contraceptive methods could cause health problems.
"The risk of serious adverse events is small in healthy women, but increases significantly if associated with the presence of other risk factors such as obesity or cigarette smoking," the company said in a statement.
Canadian retail pharmacies dispensed 274,617 Evra prescriptions from January, 2007, to November, 2007, according to IMS Health, a market research company.
The reports include the cases of two women who died - one from a heart attack, one from blood clots in her lungs - in 2006 after using the patch. Health Canada said it cannot release personal information about the women, but one was 16 years old and died several months after having a cesarean section, which may have put her at higher risk of blood clots.
Earlier this month, Health Canada published the reports in a quarterly bulletin to remind health professionals of the "potential risk factors of circulatory disorders in patients using Evra," spokeswoman Joey Rathwell wrote in an e-mail.
"Health Canada has been closely monitoring the safety of Evra through its postmarketing surveillance program. Specifically, Health Canada has been monitoring adverse effects associated with blood clots and other heart-related incidents."
While health officials haven't conclusively linked the Evra patch, manufactured by Janssen-Ortho Inc., with reported medical problems, one U.S. study found women on the patch were twice as likely to suffer blood clots as those on the Pill. Another study, however, found no increased risk for women on the patch.
In response to the studies, the U.S. Food and Drug Administration issued a strong warning that women on the patch may face a significantly higher risk of developing blood clots in their legs and lungs.
Concerns also prompted Health Canada to issue new labelling requirements in 2006 warning that women could face a higher risk of blood clots from the patch than from birth control pills and that doctors should carefully assess patients before prescribing it.
Studies are continuing and will also seek to determine whether there is a direct relationship between the patch and other medical problems, including heart attacks and stroke.
It's well known by the medical community that any hormone-based birth-control method can increase a woman's chances of blood clots, heart attack, stroke and other health problems.
