A new study shows that women using the Ortho Evra birth-control patch have double the risk of developing blood clots compared with those who take the birth-control pill, the Food and Drug Administration said Friday. The finding comes from one of two studies comparing the patch and the pill, said Ortho Women’s Health and Urology, maker of the once-a-week patch. The company, based in Raritan, N.J., is owned by Johnson & Johnson.
Last year an investigation by The Associated Press, citing federal death and injury reports, found higher rates of blood clots in women using the patch.
According to an article in the New York Times, the first study found no increased risk of clots. But the interim results from the second study suggested a twofold increase in the risk of venous thromboembolic events, or clots in the legs and lungs, in women using the patch, Ortho said.
At a briefing on Friday, Dr. Daniel Shames, director of the division of reproductive and urological drug products at the F.D.A., said the risk of a nonfatal blood clot was about one per year in 10,000 women not using a contraceptive. For those using a hormonal contraceptive like the patch or pill, the risk rises to 3 to 5 per 10,000, Dr. Shames said.
He noted that in preapproval testing of the patch on about 3,000 women, there were two reports of blood clots, but that one involved a woman who had had surgery.
The continuing studies are also looking at the risk of heart attacks and strokes among users of the two types of contraception. Currently, there is no difference, but the numbers are small, and it will take 18 more months to see if a difference occurs, Dr. Shames said.