The Ontario Superior Court has certified a class-action lawsuit against the Canadian division of Pfizer Inc., makers of the anti-smoking medication Champix, setting the company up to face allegations that it failed to adequately warn users about the drug's possible side-effects.
Lawyers for the plaintiffs, including Toronto-based firm McPhadden Samac Tuovi LLP, allege that Pfizer Canada failed to properly warn those taking the drug about potential adverse psychiatric reactions that include depression, anxiety, violent outbursts and suicidal thoughts, according to a statement from McPhadden and three other law firms.
The class action automatically includes anyone in Canada who took the drug between April 2, 2007 and May 31, 2010, and any family member or dependent of someone who may have suffered an injury related to the drug.
The allegations have not been proved in court and Pfizer denies the claims. The company said that Champix is "a proven aid to smoking cessation treatment" and has been approved for use in more than 100 countries with more than 18 million prescriptions filled.
New York-based Pfizer spent about $273-million to settle lawsuits related to the medication in the United States, according to the company's most recent annual report.
"There is no reliable scientific evidence demonstrating that Champix causes the injuries alleged. The Company stands behind Champix and Pfizer Canada provided appropriate and accurate information to regulators, physicians and patients about the safety and efficacy of Champix, which Health Canada approved, in accordance with Health Canada's labelling requirements," Pfizer said in an e-mailed statement.
In 2010, Health Canada put warnings on Champix about serious psychiatric reactions related to the drug. That same year, the French government took Champix off of its list of state-covered medications citing concerns over the drug's safety.
In 2012, Health Canada issued a statement saying: "At this time, Health Canada considers that the benefits of Champix, when used as directed on the label, continue to outweigh the risks." But it also warned patients to "stop taking Champix and seek emergency medical care if they or their families/caregivers observe unusual thoughts, feelings or behaviours."
A 2008 report from the Pennsylvania-based Institute for Safe Medication Practices said "Champix accounted for more reported serious injuries than any other prescription drug, with a total of 1,001 new cases, including 50 deaths."