TORONTO - Sixteen cases of blood clots and one heart attack among users of a birth control patch have been reported since the patch was introduced to Canada in early 2004, says a report.
Two patients have died - both in 2006 - while using the Evra patch made by Janssen-Ortho, according to the Canadian Adverse Reaction Newsletter published this month by Health Canada.
Dr. Melissa Mirosh, former fellow of the contraception advice, research and education fellowship program at Queen's University in Kingston, Ont., suggested the statistics are not a cause for concern.
"When you look at any estrogen-containing contraceptive product available on the market, whether it's the pill or the Evra patch or NuvaRing, the vaginal ring, all of them slightly increase the risk of blood clot," Mirosh, a gynecologist, said from Lethbridge, Alta., where she practises.
"There so far has been absolutely no medical proof worldwide that Evra causes clots above and beyond any of the other products on the market."
Both Health Canada and Janssen-Ortho released safety information about Evra in November 2006. The drug company noted the results of a study indicated that women using the patch had an increased risk of blood clots in the legs and lungs compared to women using an oral contraceptive. Another study, however, indicated no difference in the risk of these blood clots.
"Health Canada is currently reviewing updated information for Evra and will notify health care professionals and consumers as required," spokesman Alastair Sinclair said in an e-mail.
The woman who suffered the heart attack while using the transdermal patch died. She was a "heavy" woman and a smoker in her early 30s, and had been using the contraceptive patch for "a few months," the adverse reaction report said.
The other person who died was a 16-year-old girl, who began using the patch shortly after having a caesarean. The product monograph says women "should be encouraged to use a nonhormonal form of contraception in the three months following delivery," the report noted.
Janssen-Ortho issued a statement noting that the use of all combination hormonal contraceptives, whether in pill or patch form, is associated with increased risks of serious conditions including blood clots.
"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.
It noted some women shouldn't use hormonal contraception at all - including those with a history of blood clots, certain cancers, a history of heart attack or stroke, and women who are or may be pregnant.
Evra is safe and effective when used according to approved prescribing information, the company said.
From January to November 2007, retail pharmacies in Canada filled about 10.7 million prescriptions for contraceptives, including 274,617 for Evra, according to the market research company IMS Health.
In its 2006 advisory, the drug company said women wearing the Evra patch should avoid saunas and whirlpool baths, due to a "theoretical risk of unintentional increase in estrogen exposure from the patch."
The labelling says the patch should be discontinued at the earliest sign of blood clots - including pain in the calf, shortness of breath, chest pain or coughing blood.
The law firm Siskinds has filed a class proceeding against Janssen-Ortho Inc. related to the patch, said lawyer Matt Baer from London, Ont. A certification hearing has been scheduled for December in Toronto, where a judge will hear arguments about whether a case can proceed as a class action.
"Litigation in Canada is pending, and the company will vigorously defend the product," Janssen-Ortho manager of communications Suzanne Frost said Wednesday.
Mirosh noted that the transdermal patch delivers a comparable amount of drug to the bloodstream as the pill.
"Everybody who you start on this product - whether it's a pill or a patch or a ring - gets the same warning," she said.
"What I tell people is that any estrogen-containing birth control product will slightly raise your risk of having a blood clot in your leg or in your lung. But it does not raise it nearly as much as being pregnant or having a baby. And that risk is a very small increase."
Evra users put on a new patch once a week for three weeks, then go for a week without one. The side-effects are the same as for the pill - breast tenderness and nausea, added Mirosh, whose speaking engagements over the years have included some paid for by a number of companies that sell contraceptives, including Jannsen-Ortho.
"For women who have difficulty remembering pills it's an excellent product," she said. "It's also slightly more forgiving in that if you forget to change it after seven days, there's actually two additional days of medication in it."
"It's a unique product. There's nothing else like it."
