Bayer Birth-Control Pill May Boost Risks for Blood Clots

Bayer AG’s Yasmin and 10 other birth-control pills may pose a greater risk for blood clots in women using the drugs, and language on the labels must be strengthened to clarify those dangers, U.S. regulators said.

Pills containing drospirenone, a synthetic version of the hormone progesterone, will carry new labels about a review that showed as much as triple the risk for blood clots, the Food and Drug Administration said today in a statement. The research compared the drugs with low-dose estrogen pills. Some studies found no increased risk.

Bayer has faced a wave of lawsuits in the U.S. since 2009 alleging the Leverkusen, Germany-based drugmaker’s birth-control pills, which also include Beyaz and Yaz, caused sometimes fatal blood clots. Lawyers suing the drugmaker cited FDA reports of at least 50 deaths tied to the pills from 2004 to 2008.

“Bayer has consistently updated the FDA and other regulatory authorities around the world as new data have become available” about drospirenone-containing oral contraceptives, the company said today in a statement. Bayer “has worked with the agencies to make label updates, as appropriate.”

Known risk factors for developing a clot include smoking, obesity and family history, Bayer said. Other birth-control pills containing drospirenone include generic products made by Watson Pharmaceuticals Inc., Sandoz AG and Teva Pharmaceutical Industries Ltd.

Risk Assessment

Advisers to the FDA voted in December that the benefits of the drospirenone-containing class of birth-control pills outweigh the risks and recommended a label change to better reflect the potential for blood clots. The FDA suggested women talk to their doctors about their risk before deciding on an oral contraceptive.

“To put the risk of developing a blood clot from a birth control pill into perspective: The risk of blood clots is higher when using any birth control pills than not using them, but still remains lower than the risk of developing blood clots in pregnancy and in the postpartum period,” the FDA said today.

Of 10,000 women who aren’t pregnant and don’t use birth control pills, one to five will develop a blood clot, the FDA said. That number compares with three to nine women who use the contraceptives and 40 to 65 women of 10,000 who will develop a clot 12 weeks after giving birth, according to the agency.

Women are at greatest risk of developing a blood clot in the first year of oral contraceptive use or when restarting the pill after at least a four-week break, Bayer said in its statement.

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