Chantix is the most popular anti-smoking drug on the market, with annual sales of $800 million. It has already been linked to an increased risk of suicidal thoughts. Now experts say it may also be linked to a higher risk of heart disease -- the very thing smokers are trying to prevent by quitting -- reports CBS News correspondent Dr. Jon LaPook.
Today's study is worrisome news for the more than 7 million Americans who have taken Chantix. A new analysis links the pill to a seventy two percent increase in the risk of heart problems.
"It's causing the problem that we need to prevent among smokers," said Dr. Sonal Singh of Johns Hopkins university, who led the research. "We need to prevent cardiac disease among smokers, not increase it."
The review combines fourteen studies involving more than 8,000. While a 72 percent increased risk sounds alarming, a companion editorial titled "Is it a heartbreaker?" notes that cardiovascular problems, including chest pain, heart attack, and stroke, are still rare, occurring in only about 1 percent of patients taking Chantix.
The drug-maker, Pfizer, questions the way the analysis was conducted.
"We will continue to do a more in-depth look, as the FDA's asking us to do," said Dr. Gail Cawkwell, Pfizer's vice-president of medical affairs. "But to date we have not seen evidence of important risks to heart health from Chantix."
In mid-June, the FDA warned Chantix might be linked to a small increased risk of heart problems in smokers with heart disease. The agency tells CBS News that based on this new study, it will evaluate expanding that warning to all smokers.
The decision to prescribe Chantix comes down to a risk-benefit question with each patient, LaPook reports. On average, smoking robs people of about 10 years of life. Stopping smoking by age 50 reclaims about six of those years.
The treatment does work better than cold turkey and nicotine replacement therapy; after a year on Chantix about 20 percent of patient still aren't smoking.