Doctors fear 'pill scare' arising from birth control class-action

Sharon Kirkey, Postmedia News 


Two birth control pills targeted in class-action lawsuits in Canada pose no greater risk of blood clots than other oral contraceptives, says a national doctors group that worries a "pill scare" could lead to panic stopping of the pill and unwanted pregnancies.

The Society of Obstetricians and Gynaecologists of Canada says two studies suggesting a higher risk of venous thromboembolism among women taking Yaz and Yasmin were flawed and that the pills carry the same risk as other birth control drugs on the market.

Yaz and Yasmin are considered "fourth-generation" oral contraceptives. They contain drospirenone, a unique progestin that blocks the effects of male hormones in the body, reducing acne and premenstrual weight gain.

More than two million prescriptions for the pills were filled in Canada in 2009, according to prescription drug tracking firm IMS Brogan.

"Recent contradictory evidence and the ensuing media coverage of the venous thromboembolism risk attributed to the progestin component of certain newer oral contraceptive products have led to fear and confusion about the safety of oral contraceptives in general and drospirenone-containing oral contraceptives in particular," the gynecologists group says in an updated practice guideline issued to its members.

"We were concerned that it was going to generate another pill scare like the ones we've seen in the past," said principal author Dr. Robert Reid, a professor of obstetrics and gynecology at Queen's University in Kingston, Ont.

In 1995, the United Kingdom's Committee on Safety of Medicines issued a drug alert warning that "third-generation" pills containing gestodene or desogestrel — two other progestins — caused a twofold increase in blood clot risk compared to older formulations. Prescriptions dropped: according to an article published in the journal Human Reproduction, there were 10,000 more abortions and 30,000 more conceptions than expected in the nine months following the alert.

Venous thromboembolism — or VTE —_is a rare but potentially serious condition in which a blood clot forms in the deep veins of the legs or pelvis. Clots can break away and travel through the bloodstream to the lungs, causing a pulmonary embolism — a medical emergency in which the clot lodges in an artery, blocking blood flow to the lungs.

Obesity and smoking increases the risk of VTE. So do birth control pills: the overall risk is five in 10,000 for women who don't take the pill, and nine to 10 per 10,000 for pill users.

The risk for VTE in pregnancy can be as high as 29 per 10,000 women, Reid's group says.

A Dutch study published in the British Medical Journal last year reported a sixfold greater risk of venous thrombosis in women taking Yasmin versus other birth control pills. But Reid said the difference wasn't statistically significant because the number of women using Yasmin in the study was small, making the risk estimates unreliable.

A European surveillance study sponsored by Bayer Inc., makers of Yasmin and Yaz, that followed nearly 60,000 new users of various birth control pills found no difference in blood clot rates between Yasmin and Yaz and other birth control pills on the market.

Reid said it's believed that it's the estrogen dose that's primarily responsible for blood clots. The first birth control pills contained 150 micrograms of estrogen. Most pills on the market today contain 35 micrograms or less.

"The trade-off is that, as you lower the dose of estrogen, you start to get more spotting. Women get fed up with it and they become non-compliant — they stop using the pill and then they run a risk of getting pregnant, which has a much higher risk of blood clot than any pill," Reid says.

"When the 1995 pill scare happened in the U.K., all those extra pregnancies put women at much greater risk for blood clots."

Reid said blood clots remain one of the leading causes of death in pregnancy in developed countries.

"The message is that being pregnant carries a much higher risk of blood clot than birth control pills," Reid said. "Most pills available today are highly effective and safe. Every woman needs to understand that there is a risk of a blood clot but that this risk is low."

Symptoms include pain or swelling in the leg, or severe, progressive headaches which can be a sign of a stroke.

A lawyer for Siskinds LLP, which has launched a class-action against Bayer, said women do appear to have been "adversely impacted" while using the pills.

"We've been contacted by somewhere between 70 and 100 women who have had to have surgery to remove their gallbladders, probably another 50 or so who have experienced pulmonary embolism or deep vein thrombosis (and) a couple dozen who have had heart issues," said lawyer Matthew Baer.

The firm launched a Facebook page in October. "Close to 2,000 people have signed up for updates," Baer said.


