After numerous reports about such disturbances, the FDA had placed the most severe warning available on the medication, which led to Chantix’s sales dropping from $846 million in 2008, to $671 million last year.
To compensate for this drop, Pfizer had invested heavily in advertising and settling lawsuits against the drug. Moreover, the Pharma company had released data retrieved from a study which allegedly proved that there is no direct link between the consumption of Chantix and experiencing psychological disturbances.
To this effect, after refusing to lift the warning in 2014, the FDA decided to change its stance and drop the warning. The agency required that the medication have its side effects listed, it also specified that the label should state that Chantix is more effective than other smoking cessation therapies.
Meanwhile last June, Pfizer was forced to halt the distribution of Chantix and recall some stock after finding elevated levels of nitrosamines in the pills. However, the following month the FDA said it will temporarily allow some manufacturers to distribute the carcinogen-containing drug, below an interim limit of 185 ng per day, until the impurity can be eliminated or reduced to acceptable levels.
The FDA said the risk of exposure is relatively minimal
The US regulator said the health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in the medication. It explained that the risk of exposure to the carcinogen at interim acceptable intake levels up to 185 ng per day presents minimal additional cancer risk, in comparison to a lifetime exposure of 37 ng per day level.
Meanwhile, to help have enough supply of the medication available on the market, Canadian generic drugmaker Apotex will be temporarily allowed to distribute Apo-Varenicline tablets across the States.
Read Further: Reuters