FDA Study Links Newer Contraceptives With Increased Risk of Blood Clots

October 31, 2011 — Newer hormonal contraceptives such as Bayer's Yaz, Johnson & Johnson's Ortho Evra patch and Merck's Nuvaring present a higher risk for blood clots than older, lower-estrogen contraceptives, according to a FDA study   published on Thursday, the AP/San Jose Mercury News  reports (Perrone, AP/San Jose Mercury News, 10/27).  Earlier this year, FDA launched a safety review of birth control pills containing drospirenone -- such as Yaz and Yasmin -- after two studies found a two to three times greater risk of blood clots associated with the products compared with birth control pills containing levonorgestrel, a type of progestin (Women's Health Policy Report, 9/27). Other studies have linked an increased risk of clots with the patch and vaginal ring, but FDA has not launched a formal safety review of those methods.

 For the new study, FDA researchers examined medical records for more than 835,000 women who used hormonal contraceptives from 2001 to 2007. They compared the rate of blood clots among women taking the newer methods with those taking levonorgestrel pills.

 Newer oral contraceptives containing drospirenone were associated with a 1.74 greater risk of blood clots in the veins, compared with older contraceptives. Women who used the norelgestromin/ethinyl estradiol transdermal patch had a 1.55 times greater risk of the clots, while women using the etonogestrel/estradiol vaginal ring had a 1.56 times higher risk. Among women older than age 35, taking drospirenone products for the first time also was associated with an elevated risk of arterial blood clots.

 As of this week, FDA said it has not reached a conclusion on the risk of drospirenone pills. The agency will present its findings at a joint meeting of the Reproductive Health Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee on Dec. 8 (Gever, MedPage Today, 10/27).