Two studies, both sponsored by Bayer, found drospirenone to be as safe as other progestins.
In one, scientists at the Center for Epidemiology and Health Research in Berlin tracked for over a year more than 58,000 European women who had been prescribed various forms of birth control pills. They concluded that there was no greater risk of mortality, cancer or cardiovascular problems from pills with drospirenone than other oral contraceptives.
In the other, i3 Drug Safety, a company that provides pharmaceutical services to drug companies, followed for seven months almost 70,000 U.S. women taking various kinds of oral contraceptives, including ones containing drospirenone. The researchers concluded that more than 9,000 women would need to take Yaz or Yasmin for one extra case of deep vein thrombosis to occur.
Attorney A.J. de Bartolomeo, a partner at the San Francisco law firm Girard Gibbs who is helping shepherd lawsuits against Bayer, said women should be warned if there is even a slightly greater risk.
"We believe it's a dangerous drug, and the most important thing here is to allow women to make an informed choice and know what the comparable risks are before they put a drug in their body," De Bartolomeo said.
As of November, the Food and Drug Administration had received reports of 993 cases of pulmonary embolism (blood clots in the lungs), 487 of deep vein thrombosis (clots in the deep veins) and 229 of other blood clots for the two medications combined.
Some physicians think the attention the medications have received serves only to frighten women.
"Patients get hurt with these types of lawsuits," said Dr. Andrew Kaunitz, a professor of obstetrics and gynecology at the University of Florida's College of Medicine who has consulted with pharmaceutical companies, including Bayer. "They get scared not only with this one pill but all types of contraceptives."
Kaunitz said all types of oral contraceptives increase the risk of blot clots three- to fourfold. But, he added, pregnancy increases the risk of blood clots six- to 10-fold. He said he wouldn't recommend patients change their pills if Yaz or Yasmin are working well for them.
Dr. Anitra Beasley, a physician at the Leadership Training Academy of Physicians for Reproductive Choice and Health and a fellow at Columbia University in New York, has been telling her patients the same thing. She said many come in with worries after seeing commercials questioning the pills' safety — and that some have stopped taking Yaz only to return with an unwanted pregnancy.
"We've got great news from the FDA, that has looked at all of these studies and assures us that the best-done study shows that the risk of clots with Yaz is not greater than on any other birth control pill," she said. "And we have read all of the same literature and have come to the same conclusions — we didn't change our practices."
Dr. Anita Nelson, a professor of obstetrics and gynecology at UCLA's David Geffen School of Medicine who serves on the advisory board of Bayer, said the litigation runs the risk of "scaring the heck out of women."
"I have noticed a pattern, that every time a method of birth control gets popular it gets sued," she said. "The same thing happened for the patch; and we lost Norplant [for the same reason] even though it was very safe and effective."