July 5, 2011

Chantix Causes 72% Rise In Risk Of Heart Attack

According to a new study described in the Canadian Medical Association Journal, healthy, middle-aged smokers who take the most popular smoking cessation drug on the market have a 72 percent increased risk of being hospitalized with a heart attack or other serious heart problem.

"People want to quit smoking to reduce the risk of cardiovascular disease but in this case they're taking a drug that increases the risk for the very problems they're trying to avoid," Sonal Singh, M.D., M.P.H., an assistant professor of general internal medicine at the Johns Hopkins University School of Medicine, said in a statement.

The researchers reviewed and analyzed 14 double-blind, randomized, controlled clinical trials involving over 8,200 healthy people who received either Pfizer's varenicline or a placebo.

The study found that the increased risk of a major harmful cardiovascular event requiring hospitalization such as a heart attack or arrhythmia for those using varenicline was 72 percent.

The average age of the study participants was less than 45 years and the majority of them were men.

Varenicline has been shown to increase the chances of a successful quit attempt, compared to unassisted smoking cessation attempts.

Singh said that varenicline already carries a boxed warning because of its association with suicidal thoughts and behaviors.

"We notified the FDA of our cardiovascular safety concerns with Chantix earlier this year," Singh says.

The FDA announced on June 16 that people with existing heart disease who use varenicline have a slightly increased risk of a heart attack or other cardiovascular event.  However, the new study found that varenicline substantially increased the risk of a serious cardiovascular event even among smokers without heart disease.

"I think our new research shifts the risk-benefit profile of varenicline," Singh said in a statement. "People should be concerned. They don't need Chantix to quit and this is another reason to consider avoiding Chantix altogether."

The researchers emphasized the need to quit smoking, but suggest that varenicline may not be the right drug to help kick the habit.

Singh said questions about the drug's cardiovascular disease risks have been raised sine varenicline went on the market in 2006.

Singh said the FDA used a "fast-track" review process in allowing varenicline to be sold in the U.S. and would like regulators to take a new look.


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