Pfizer
Researchers combined data from 14 clinical trials to find that Chantix increases the rate of cardiovascular events -- heart attacks, strokes, and the like -- by 72%. While that sounds awfully bad, we have to keep this in context. The rate only increased from 0.82% for people taking placebo to 1.06% for patients taking Chantix. If the data is correct -- and there are certainly issues with doing this type of meta-analysis -- for every 400 or so people without cardiovascular risk, Chantix creates one additional cardiovascular event.
Of those 400 patients, about 80 will quit for an entire year compared to around 30 for those on placebo. Are the health benefits of 50 smokers quitting greater than one cardiovascular event? I'd guess yes, but calculating it would require yet another meta-analysis, and we're already on a slippery slope drawing any conclusions here.
Pfizer's best hope for Chantix is that patients ignore the warning section on the drug's label, which may be updated at some point to contain the new cardiovascular risk. Given that smokers have been disregarding cancer warning labels on cigarettes sold by Reynolds American
If not, GlaxoSmithKline