A class action lawsuit has been filed in B.C. Supreme Court against the maker of a blood-thinning drug, alleging that serious potential side effects aren't clearly disclosed.

Gladys Chouinard, who lived in B.C., was prescribed Pradaxa following a heart attack and a valve replacement. The lawsuit says she bled to death a month after she began taking the medication.

Pradaxa

A class action suit has been filed in B.C. against the maker of Pradaxa, a blood-thinning drug, alleging that the warning label didn't contain adequate information. (Pradaxa.com)

Her daughter, Marilyn Tanguay, claims the company didn't make it clear that there was no antidote for the drug in the event of a major bleeding event  a known side effect of many blood thinners.

Bryan McPhadden, the lawyer representing the class action, says the fact there is no antidote wasn't made clear on the drug's labelling.

"It should be profiled in the warning section of the product monographs, and that was not the case when Pradaxa first came on the market," he said. "For some unknown reason, it was contained in the overdose section. We say that is entirely unhelpful, because overdose is not usually a problem."

McPhadden says the clearest labelling is essential for doctors and patients to be able to make the right choices for themselves.

"If you were concerned about a possible bleeding event, you might have not taken Pradaxa at all. Or, if you suffered from bleeding, at least you would know where to look."

Health Canada approved Pradaxa for use in 2008. It was one of the first blood thinners that didn't require regular blood testing.

 U.S. lawsuit settled

In May, the drug's manufacturer, Boehringer Ingelheim, agreed to pay $650 million U.S. to settle lawsuits in the United States

When contacted by CBC, the company issued a written response saying there are approximately 4,000 U.S. claims that the company seeks to resolve with that settlement.

"BI expects most, if not all, of the plaintiffs to accept the terms of the settlement and BI will vigorously defend against those who do not." 

"There are currently eight product liability claims in Canada against Pradaxa. These claims, as any other proceedings outside the U.S., are not covered by the terms of the U.S. settlement and we intend to continue to vigorously defend each and every case outside the settlement agreement."

“Time and again, the benefits and safety of Pradaxa have been confirmed," said the statement.

“BI stands resolutely behind Pradaxa and believed from the outset that the plaintiffs’ claims lacked merit. Notwithstanding our strong belief that we would prevail in these lawsuits, this settlement allows BI to avoid the distraction and uncertainty of lengthy litigation and focus on our mission of improving patients’ lives.”

With files from the CBC's Tina Lovgreen