FDA ‘ups’ safety warnings for blood clots on birth control pill labels

By Dr. Ananya Mandal, MDApr 11 2012

According to federal health regulators more information needs to be added to labels on a popular class of birth control pills that includes Bayer AG's Yaz and Yasmin, to show they may raise the risk of blood clots. A clot in blood vessels can prove fatal if it breaks loose and travels to the lungs, heart or brain.

It is known that all birth control pills increase a woman's chances of getting potentially fatal blood clots. But the U.S. Food and Drug Administration (FDA) said on Tuesday that some studies showed the danger may be even higher for more recent pills that contain the compound drospirenone, a synthetic hormone.

“The revised drug labels will report that some epidemiologic studies reported as high as a three-fold increase in the risk of blood clots for drospirenone-containing products ... whereas other epidemiological studies found no additional risk,” the FDA said in a statement. The FDA's own study found that 10 in 10,000 women taking pills with drospirenone would get a blood clot per year, compared with about six in 10,000 women taking older contraceptives. To put the risk into perspective however, the FDA added that the risk of blood clots from pregnancy is even higher than any risk from birth control pills.

The announcement comes after an advisory committee of outside experts to the FDA voted in December for a label revision for pills with drospirenone, calling for clearer information about their risks and benefits. The experts agreed that these pills' benefits outweighed their risks, since some studies found the pills did not increase blood clot risks.

During the December panel meeting, some women's advocacy groups called for the pills to be taken off the market, as the studies that viewed pills favorably were industry-funded. In January, the Project on Government Oversight urged the FDA to hold a new vote about the birth control pills after a study showed four of the FDA's advisers had ties in the past to makers of pills containing drospirenone. The FDA said past ties to industry are usually not considered conflicts under the law.

Cynthia Pearson, executive director of the National Women's Health Network, who testified at the December meeting, said that a simple label change would not necessarily protect women from blood clots. “I fear that if the FDA holds another public hearing three years from now, there will be a new group of women telling sad stories about the harm done to their health by clots,” she said on Tuesday.