Chantix and cardiovascular risk: meta-analysis

Singh et al report in a meta-analysis of 14 randomized trials (n=8,216) that varenicline was associated with an odds ratio of 1.72 for serious cardiovascular events compared to placebo. The absolute increased risk was 0.24% (a number needed to harm of 400, while varenicline has a number needed to treat of ~10 to get one quit smoker). The authors' methodology is challenged by multiple credible online commenters, worth reading before throwing Chantix under the bus. CMAJ online July 4 2011.