Research just published in the British Medical Journal compares newer “fourth generation” birth control pills, such as Yaz, Yasmin, Ocella and Beyaz, which contain the progestin drospirenone, with older birth control pills that use levonorgestrel.
Researchers from the Boston Collaborative Drug Surveillance Program at Boston University School of Medicine looked at nearly 900 women on birth control since 2002. For women taking Yaz or Yasmin, the rate of blood clots was 30.8 per 100,000 person-years. For women talking levonorgestrel-based pills, the rate was only 12.5 per 100,000 person-years.
The researchers adjusted for obesity and other factors. They found that women younger than 30 who used Yaz or Yasmin appeared to have an even greater disparity in the rate of blood clots than if they took older birth control pills, with an incidence rate of 24.8 per 100,000 for the new pills compared to only 5.39 per 100,000 if they took levonorgestrel.
“These findings support more recent studies that suggest that drospirenone oral contraceptives are not as safe as levonorgestrel oral contraceptives with respect to venous thromboembolism and, in the absence of other considerations, should not be the first choice in oral contraception,” the study’s authors concluded.
The study comes out just days after other research published by the British Medical Journal examined the potential risk of gallbladder disease from Yaz and Yasmin, finding that women taking the newer pills may be 20% more likely to experience gallbladder disease than those taking levonorgestrel. However, those researchers determined that while the risk was statistically significant, it was not clinically significant.
Bayer faces about 7,000 Yaz and Yasmin lawsuits over the birth control pills. The complaints involve claims filed by women who suffered a stroke, pulmonary embolism, deep vein thrombosis, gallbladder disease or other potential side effects from Yaz and Yasmin birth control.
The federal Yaz litigation has been consolidated and centralized for pretrial proceedings as part of an MDL, or multi-district litigation, in the U.S. District Court for the Southern District of Illinois. There are also hundreds of cases filed at the state level in New Jersey and Pennsylvania.
The first Yaz trials are expected to begin early next year. A small group of cases, known as bellwether lawsuits, are being prepared for early trial dates to help parties to gauge the strengths and weaknesses of cases involved in the litigation. The outcome of the bellwether trials may facilitate a possible settlements for blood clots from Yaz and Yasmin.
Yaz and Yasmin Gallbladder Disease Risk Higher Than Other Pills: Study (4/21/2011)
Birth Control Pill Blood Clot Risk Higher Among Some Drugs: Study (8/14/2009)