Study Confirms Blood Clot Risk From Drospirenone Birth Control Pills


The oral contraceptive drospirenone—commonly known as Bayer’s brands Yaz and Yasmin—have been linked to blood clot risks in recent study.

The Danish study
found that women taking Yas and Yasmin are likely doubling their risks for venous thromboembolism (VTE) when compared to women taking levonorgestrel-containing oral contraceptives (OCs), said MedScape. The study was published yesterday in the British Medical Journal (BMJ).

Øjvind Lidegaard, MD, Study author and professor of obstetrics and gynecology, University of Copenhagen, Denmark, and colleagues wrote, said MedScape: “The influence of specific types of combined [OCs] on the risk for thrombotic events remains the most important safety issue for these products.” This study endeavored to reevaluate Danish registry data and review differences between patients taking drospirenone—Yas and Yasmin—and patients taking leonorgestrel-containing OCs, said MedScape.

The nationwide historical cohort took place from 1995 through 2009 and involved Danish Women between 15 and 49 years of age, said MedScape. Women with a prior VTE history, who underwent reproductive surgery, who suffered from coagulopathy or cancer, who used ovarian stimulation drugs, or who had been pregnant were either censored or excluded. Classification involved type, dose, and for how long OCs were taken; education level, body mass index (BMI); and history of tobacco use, noted MedScape; 1,296,120 women were included and 4307 (1.9%) first-time VTE events were recorded (26.2%: pulmonary embolism, 63.6%: deep venous thrombosis, 6.6%: unspecified deep vein thrombosis).

The study found that, when compared to women who do not take OCs, those on a levonorgestrel OC experienced a three-fold risk for confirmed VTE, while OC users who took Yas, Yasmin, desogestrel, gestodene, or cyproterone acetate, experienced a six-to-seven-fold increased risk for VTE, said MedScape. The study was restricted to confirmed events—67% of all identified VTEs—which increased data strength, said Dr. Lidegaard and colleagues, said MedScape.

A U.S. Food and Drug Administration (FDA) drug safety communication revealed that initial study results found that women taking Yaz, Yasmin and other drospirenone OCs could face a 1.5-fold increase for blood clots. Hormonal OCs are known to increase VTE risks, but the FDA data involving 800,000 women suggests more serious risks, as do prior BMJ-published studies, which indicate risks that are double-to-triple that for typically expected risks for clotting.

Independent commentator Susan Jick, DSc, Director of the Boston Collaborative Drug Surveillance Program, Boston University School of Medicine, Massachusetts, confirmed the findings. “This study supports the research that suggests that these OCs do carry a higher risk of VTE compared to the levo[norgestrel] OC,” she told MedScape Medical News. “All things being equal, I would not prescribe a third-generation OC or a drospirenone OC, given the higher VTE risk.” In accompanying editorial, Philip C. Hannaford, MD, Grampian Health Board chair of primary care at the University of Aberdeen, United Kingdom, said “Although unpalatable to some, it is difficult not to conclude that combined [OCs] with desogestrel, gestodene, or drospirenone confer a higher risk of [VTE] than those with levonorgestrel.”

The FDA’s advisory panel will meet later this year to determine if Yaz, Yasmin, and other similar medications increase blood clot risks and will review information on the Yaz and Yasmin brands and their generic equivalents, all of which contain the controversial, synthetic progestin, drospirenone, making them different from other OCs. Drospirenone can increased potassium levels, which can cause hyperkalemia in some. Hyperkalemia can lead to serious heart and health problems.