Recently, a large study comparing Chantix to a placebo found a higher occurrence of cardiovascular events, including heart attack, stroke, and death. The FDA cautions, “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.”
Pfizer, the manufacturer of Chantix, was required to conduct the study after the FDA first warned about the potential risk in a Safety Communication in June 2011. The manufacturer conducted a study called a meta-analysis, in which data from multiple clinical trials is combined and researchers look for an increased risk of certain side effects. The results of the meta-analysis were similar to results from an earlier clinical trial that also found Chantix associated with cardiovascular problems.
The study combined data from 12 studies conducted by Pfizer, which involved 7,002 patients (of whom 4,190 used Chantix and 2,812 used a placebo). The researchers then analyzed the risk of death due to heart problems, non-fatal heart attacks, and non-fatal strokes. Within 30 days of discontinuing Chantix or the placebo, cardiovascular events occurred in 0.31% of Chantix patients and 0.21% of placebo patients.
The FDA concluded:
“Although these findings were not statistically significant, they were consistent. Because the number of adverse cardiovascular events was small overall, the power for finding a statistically significant difference in a signal of this magnitude is low.”
Although Chantix may increase the risk of heart problems, smoking cigarettes is also associated with an increased risk of heart disease, lung disease, and some cancers. Therefore, the FDA recommends that patients should carefully consider the risks and benefits of Chantix with their doctor.