Ads that subtly promote the smoking cessation drug Champix are popping up in downtown Montreal, but the campaign is raising concerns after a recent study linked the drug to heart problems.

The drug, manufactured by Pfizer, is the subject of three Health Canada safety advisories.

The warnings involve reports of possible adverse reactions including depression, hostility, and increased risk of suicide.

Champix, the brand name for varenicline, was developed by Pfizer and approved for use in Canada in January 2007.

The drug is designed to reduce the pleasure of smoking and the withdrawal symptoms that often make people resume the habit.

A study published in the Canadian Medical Association Journal in July found people taking the drug had a 72 per cent higher risk of developing serious heart problems.

Health Canada launched a safety review in June after an American study raised concerns about risks for patients with cardiovascular disease. 

The ads in question feature the words "I did it!" on a green background with the drug’s website tagged underneath.

In Canada, as long as an ad doesn’t specify the disease or condition a drug is supposed to treat, it’s legal, even if the drug has been flagged for review by Health Canada.

In the U.S., stricter advertising standards prohibit Pfizer from using the same marketing for the drug.

Complies with regulations

In an emailed statement, Pfizer said the ads comply with all federal regulations.

"The campaign was also reviewed and approved by Advertising Standards Canada (ASC) as part of their pre-clearance service," the statement reads.

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The ads, which have been popping up in downtown Montreal, don't specify what the drug is supposed to treat or the risks associated. (CBC)

"The goal of the CHAMPIX direct-to-consumer campaign is to encourage an open dialogue between consumers and health-care professionals.

"During the course of this dialogue, issues surrounding the appropriateness of a given medication or treatment will be discussed between the health-care professional and the patient."

'Serious safety signals'

Barbara Mintzes, a professor of epidemiology at the University of British Columbia, said the ads are "outrageous," given the side-effect concerns that have been identified.

She is calling on Health Canada to shut down the company’s direct-to-consumer marketing.

"I was very upset to see the ads," she said.

"When there are serious safety signals about a drug, those drugs should not be advertised to the public."

In a statement released last month, Health Canada said it has now completed its review, which found a "slightly increased number of patients" experienced serious heart-related problems compared to the placebo group.

It concluded that Champix is an effective aid for quitting smoking and its benefits outweigh the risk.

Health Canada noted that "smoking by itself is a major known risk factor for cardiovascular disease and that patients with cardiovascular disease can benefit greatly from quitting smoking."