December 9, 2011 — An FDA advisory panel on Thursday recommended additional safety warnings on the risk of blood clots from newer birth control pills that contain the hormone drospirenone, the Washington Post reports. Drospirenone is a form of progestin found in Bayer's Yaz, Yasmin, Beyaz and Safyral, as well as other birth control pills (Stein, Washington Post, 12/8).
The panel voted 21-5 in favor of altering Bayer's labels, concluding that the current label is "inadequate and incomplete," according to panel member Richard Bockman of New York's Hospital for Special Surgery. He added, "Adverse events have to be made graphic so physicians and patients are aware of the consequences."
The panel voted 15-11 to affirm that the benefits of the drugs for preventing pregnancy outweigh their risks. Panelists who voted against this recommendation cited the numerous alternatives available for women who wish to take oral contraceptives.
The panelists spent nine hours debating inconsistent data from studies on the risk of blood clots (Perrone, AP/San Francisco Chronicle, 12/8).
Preliminary results from a FDA safety review of more than 800,000 women found a 1.5 times greater risk of clots associated with drospirenone-containing contraceptives. However, six other studies show conflicting results, with some data showing a higher risk and others showing no increased risk.
Bayer has said its analysis of available scientific evidence shows that the risk of developing a blood clot associated with pills containing drospirenone "is comparable" with that of other birth control pills (Women's Health Policy Report, 12/8). The company also has said that studies that find a higher risk have methodological flaws (Belluck, New York Times, 12/8).
Several panelists pointed out that only studies sponsored by Bayer found that the drugs did not increase the risk of blood clots. "I found that disturbing," said panel member Maria Suarez-Almazor of MD Anderson Cancer Center (Selyukh, Reuters, 12/8).
FDA has not set a schedule for making any changes to the labels. Although the agency is not required to follow the advice of its advisory panels, it often does (AP/San Francisco Chronicle, 12/8).