It has long been known that there is an increased risk of cardiovascular complications including, for example, blood clots known as venous thromboembolisms ("VTEs") that result from the use of combined hormonal contraceptives ("CHCs"). Most CHCs are birth control pills containing the hormones estrogen and progestin. Recently, several new CHCs have been introduced into the market, and concerns have arisen regarding whether the cardiovascular risks are greater among these new preparations. The new CHCs are drospirenone/ethinyl estradiol tablets, the norelgestromin/ethinyl estradiol transdermal patch, and the etonogestrel/ethinyl estradiol vaginal ring. Drospirenone is a synthetic progestin, and the drospirenone tablets are marketed under the names Yaz®, Yasmin®, Beyaz®, and Safyral® (along with various generics). On October 27, 2011, the FDA published the final study report from its evaluation of these risks along with a safety statement regarding the possible increased risk of VTEs from drospirenone tablets.
FDA's study was a retrospective study entitled, "Combined Hormonal Contraceptives (CHCs) and the Risk of Cardiovascular Disease Endpoints" and it compared the risk of blood clots, among other things, in women who took three newly-marketed CHCs to women who took four older CHCs. The study examined the medical histories of 835,826 women from 2001 to 2007 and found that women taking the newly-marketed CHCs, including the drospirenone tablets, had a significantly higher risk of VTEs. Among only the users of the new formulations, the drospirenone tablets were the only ones with a significantly higher risk of VTEs. In conclusion, FDA stated that this study provided further evidence to link the drospirenone tablets with an increase in VTEs as compared to the other low-dose CHCs.
However, FDA has also seen conflicting results from six other studies of drospirenone pills and the risk of VTEs. Because of the conflicting results, FDA will hold a joint meeting with scientific advisors from the Reproductive Health Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee on December 8, 2011. At the meeting FDA will review the results of its study and discuss the risks and benefits of drospirenone birth control pills, especially the risk of blood clots associated with these pills.