UPDATE 1-US group wants FDA to pull J&J birth control patch

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By Susan Heavey

WASHINGTON, May 8 (Reuters) - A U.S. advocacy group is urging the Food and Drug Administration to pull Johnson & Johnson's (JNJ.N: Quote, Profile, Research) birth control patch from the market after studies found an increased risk of dangerous blood clots.

In a petition filed with the FDA on Thursday, Public Citizen's Health Research Group said the amount of estrogen released from the Ortho-Evra patch varies widely among individual women, and those who absorb too much were at greater risk for blood clots and and other painful side effects.

"The considerable safety concern of high-dose, variable estrogen exposure tips the balance of risks and benefits against the availability of Ortho-Evra as a contraceptive," wrote Sidney Wolfe, head of the research group.

Ortho-Evra has seen its use slip in the wake of such data, which led to warnings on the patch's label as recently as January, when a study of women ages 15 to 44 found blood clots known as venous thromboembolisms were about twice as likely in women using the patch versus birth control pills.

The FDA at the time said the patch was safe and effective when used as directed and urged patients to talk to their doctors about the risk.

Estrogen used in contraceptives has long been known to increase the risk of blood clots, which can trigger heart attacks or strokes. Women who use Ortho Evra can be exposed to about 60 percent more estrogen than pill users.

"If Ortho-Evra had been designed as a pill, it is unlikely to have been approved because of its increased estrogen content," Wolfe said.