If you take Bayer's Yaz aka Yasmin or other birth control pills containing drospirenone, a man-made version of the hormone progesterone, you'll soon notice new, stronger warning labels adorning their packages. That's because these particular pills may put women at greater risk for blood clots--as much as 75 percent higher--compared to other progestin-containing oral contraceptives.
The potentially higher risk associated with these newer contraceptives prompted the U.S. Food and Drug Administration to issue a safety alert.
The new labels will warn patients that "some epidemiologic studies reported as high as a three-fold increase in the risk of blood clots for drospirenone-containing products when compared to products containing levonorgestrel or some other progestins, whereas other epidemiological studies found no additional risk of blood clots with drospirenone-containing products. The labels also will include a summary of the previously released results of an FDA-funded study of the blood clot risk."
Yaz received FDA approval in 2006 and became the top selling birth control pill, marketed for its additional benefits of controlling premenstrual syndrome and preventing acne.
Despite the lack of a definitive risk conclusion on the new labels, the FDA advisers voted 21-5 in favor of new labels for these birth control pills, according to this Time article which offers background on what spurred the new guidelines.
The Time article also put the risk into perspective:
"The absolute risk of developing a blood clot is still low, however. FDA researchers found that the rate of blood clots was 10 in 10,000 women taking pills with drospirenone, compared with 6 in 10,000 women taking older oral contraceptives. By contrast, the blood-clot risk in women who are pregnant or have just given birth is 20 in 10,000 women. But small increases in risk are serious, since blood clots can cause potentially fatal heart attacks, strokes and pulmonary embolisms."
The FDA alert also recommended that women should discuss their risk for blood clots with their healthcare professional when deciding on a birth control method.