When the FDA first expressed concerns about the possible increased risk of cardiovascular adverse events associated with the smoking-cessation drug Chantix (varenicline) in a Drug Safety Communication (DSC) dated June 16, 2011, the agency said it would require Pfizer, the drug’s manufacturer, to conduct a meta-analysis of randomized, placebo-controlled trials of the drug. In a DSC issued December 12, 2012, the FDA presented that meta-analysis. Results indicated a higher occurrence of major adverse cardiovascular events (a combined outcome of cardiovascular-related death, nonfatal heart attack, and nonfatal stroke) observed in patients using Chantix compared with those on placebo. However, these events were uncommon in both the Chantix and placebo groups, and the increased risk was not statistically significant, which means it is uncertain whether the excess risk for the Chantix group was due to the drug or due to chance.
The FDA advised health care professionals to weigh the risks of Chantix against its benefits, while noting that smoking is a major risk factor for cardiovascular disease and that Chantix is effective in helping patients quit smoking and abstain from it for as long as one year. “The health benefits of quitting smoking are immediate and substantial,” the agency emphasized in the communication. The Warnings and Precautions section of the Chantix label has been updated to include the results of the meta-analysis.