New warnings are being added about the increased risk of blood clots from Yaz and Yasmin, as well as all birth control pills that use the progestin drospirenone.
The FDA issued a drug safety communication on Tuesday, announcing the updated warning label following a review of a number of studies that suggest drospirenone birth control pills may more dangerous than other oral contraceptives containing levonorgestrel or some other progestins.
Drospirenone is a newer type of progestin that is used in combination with estrogen to prevent pregnancy. It was first introduced in Yasmin birth control by Berlex Laboratories, which was later acquired by Bayer. Yaz is an updated version of the birth control pill, and Bayer recently introduced a third variation, marketed as Beyaz, which also includes a folate supplement. There are also a number of generic and low-dose versions available.
The FDA indicates that there are still a number of factors that make drospirenone’s link to increased blood clot risk unclear. The studies do not provide the agency with consistent estimates of the comparative blood clot risks between pills with and without drospirenone, and they also do not account for some important patient characteristics that could affect blood clot risk.
The revised labels will state that some studies report that Yaz side effects may triple the risk of blood clots when compared to pills containing other progestins, but notes that some studies found no increased risk. The labels will include data from the FDA’s own study, which determined that drospirenone-based birth control pills were associated with a 1.5-fold increase in blood clot risk.
The new warnings are likely to factor into product liability lawsuits filed over the birth control pills, which allege that Bayer failed to adequately research the medication or provide clear warnings about the increased risk of blood clots compared to older birth control pills.
Earlier this year, the federal judge presiding over all lawsuits filed in U.S. District Courts throughout the United States ordered Bayer and plaintiffs’ lawyers to engage in Yaz settlement negotiations before the first cases are submitted to a jury. Known as bellwethers, those early trial dates are often used to facilitate discussions to settle other lawsuits, and may help the parties gauge how juries are likely to respond to evidence that is likely to be introduced in multiple cases.