Safety concerns with the popular birth control pill Yaz increased yesterday as federal health scientists reported that the Bayer drug and other newer birth control treatments are adding to previous evidence which showed that they increase the risk of dangerous blood clots more than older medications.
A new study released by the Food and Drug Administration reviewed the medical history of more than 800,000 U.S. women taking different forms of birth control between 2001 and 2007. On average, woman taking Yaz had a 75 percent greater chance of experiencing a blood clot than women taking older birth control drugs.
European regulators said that they would revise prescribing information for relevant products to include the new findings.
Yaz contains estrogen along with a next-generation synthetic hormone called drospirenone, which is known to increase potassium levels in the blood. FDA compared medical records of women taking the drug with those taking the older drug levonorgestrel.
Yaz, Yasmin and related drospirenone-containing pills were Bayer's second-best-selling franchise last year at $1.6 billion in global sales.
In 2009, the FDA took the unusual step of ordering Bayer to run corrective TV advertisements on Yaz, saying the drugmaker's marketing campaign overstated the drugs' ability to prevent acne and premenstrual syndrome.
Bayer Healthcare, a division of the German conglomerate, said it "is currently evaluating this publication and cannot comment at this point in time."
Nicola Goss, 35, collapsed suddenly after complaining of stomach cramps and sickness after a blood clot developed in her bloodstream.
Nicola, who had been taking the pill for seven years, was fit and healthy and had rarely seen her doctor apart from at regular check ups.
Rob Dugay, her partner of six years, said: 'The coroner has said the pill may have played a part in causing the clot. I can't believe that something that's such a part of every day life could have caused her death.'
As little as 1 in 300 women per year who are taking birth control pills may developing a blod clot. For women with thrombophilia, hypercoagulability or prothrombotic states, this risk is significantly higher.
The agency also reported higher complications in women using the Ortho Evra patch from Johnson & Johnson and the Nuvaring vaginal ring from Merck & Co. Inc. Those drugs combine estrogen, which is present in all birth control pills, with two other synthetic hormones launched in the last decade.
The FDA said it hasn't reached a final conclusion on the drugs' safety but will hold a meeting with scientific advisers Dec. 8.
Consumer safety advocates have criticized the agency for approving newer, more expensive birth control drugs when cheaper, generic drugs with established safety records are widely available.
"At a certain point we have to ask why the FDA continues to approve drugs that are less safe and have no benefit compared to drugs already on the market," said Dr. Diana Zuckerman, president of the National Center for Women and Families, a consumer group for women's health issues. "With all these different birth control options, why take the most expensive one that can also kill you?"
Recent studies have reached differing conclusions on the risks of newer birth control pills.
A study published earlier this week involving more than 1 million Danish women found that women taking Yaz and other newer medications had twice the risk of blood clots as women taking the older hormone levonorgestrel. The findings appeared Tuesday in the British Medical Journal.
However, two studies published in 2007, conducted as part of the postmarketing requirements of the FDA or European regulators, did not find any difference in blood clotting between the two comparable groups.
Birth-control pills that contain drospirenone include Bayer's Yaz, Yasmin, Beyaz, Safyral; Sandoz's Syeda and Loryna; as well as Barr Laboratories' Ocella, Watson Pharmaceuticals' Zarah and Teva Pharmaceuticals' Loryna.
The new patches (transdermal contraceptives) may increase this risk even more. The amount of estrogen absorbed from the patches has been reported to be 60 percent higher than the amount delivered by the pills. Little information about the risk of blood clots with birth control rings is available. Like patches and most birth control pills, these devices also contain an estrogen and a progestin; thus they probably carry a risk of thrombosis similar to that of birth control pills or patches.
A study from Belgium showed that long-term use of oral contraceptives -- at least the high-estrogen ones sold decades ago -- might increase the chances of having artery buildups that can raise the risk of heart disease.
Other research confirmed that the main ingredient in the contraceptive shots -- depo medroxyprogesterone acetate or DMPA -- can cause significant bone loss when used long term. And, say experts, the younger you are when you begin using this contraceptive, the greater your risk of bone-related problems later in life.
In 2005, Johnson and Johnson subsidiary Ortho McNeil, makers of Ortho Evra, issued a warning saying women using the patch will be exposed to about 60% more estrogen than those using typical birth-control pills because hormones from patches get into the bloodstream and are removed from the body differently than those from pills.