Pharma Pfizer halts global Chantix distribution after testing flags impurities

Smokers looking for Pfizer's cessation med Chantix may have a tough time finding the drug as the pharma giant has halted global distribution on impurity concerns.

After finding unacceptable levels of potential carcinogens called nitrosamines in certain Chantix lots, Pfizer has halted worldwide distribution of the popular smoking cessation medicine.