OTTAWA, Ontario, June 10, 2011 ( – Health Canada has announced it will be reviewing the safety of the contraceptive pills Yaz and Yasmin over concerns users may have a two to three times greater risk of developing blood clots, compared to those who use other brands of contraceptive pills.

Health Canada’s decision follows in the footsteps of an announcement in May that the United State’s Food and Drug Administration (FDA) was also reviewing the safety of the contraceptive pills.

“Blood clots are a rare but well known side effect associated with all birth control pills,” said a statement from the Canadian federal department.

Recent studies, including two new studies published in the British Medical Journal, suggest the risk of venous thromboembolism (blood clots) with drospirenone-containing contraceptive pills may be two to three times greater than with birth control pills containing another type of progestin.

Drospirenone is one form of the female sex hormone known as progestin.  While most contraceptive pills contain a combination of progestin and estrogen, some contain different types of progestin only.

In Canada, Yaz and Yasmin, produced by Bayer, are the only contraceptive pills containing drospirenone.

Bayer is facing 7000 Yaz-related lawsuits in the U.S. from women who say the drug manufacturer misrepresented the dangers associated with using the birth control pills – side effects including stroke, cardiac arrest, blood clots, and gallbladder problems.

One wrongful death lawsuit involves an 18-year-old New Jersey college student, Michelle Pfleger, who died of cardiac arrest after taking Yaz for acne treatment. A blood clot had lodged in her lungs resulting in her sudden death on her way to classes on September 24, 2010. Her mother Joan Cummins filed suit against Bayer on May 10.

In light of the concerns, Health Canada announced they will be “investigating and reviewing the studies.” 

“Health Canada will take appropriate action as necessary once the review is complete,” said the statement on the federal website. “This could include informing health professionals and Canadians of new safety information resulting from Health Canada’s review.”

Meanwhile, Bayer issued a press release claiming studies have confirmed the risk from Yaz and Yasmin is comparable to other contraceptives.

“Bayer’s oral contraceptives have been and continue to be extensively studied worldwide and for most healthy women of reproductive age, the benefits of [oral contraceptives such as Yaz and Yasmin] will outweigh the risks when used as directed,” the company said.

According to Bayer, the risk of venous thromboembolism (blood clots) for women taking Yaz or Yasmin is also “lower than the risk for VTE associated with pregnancy and delivery.”

For other Health Canada drug information and other side effects of hormonal contraceptives, click here.