Pfizer has recalled four more lots of its smoking cessation drug Chantix after finding some pills contain elevated levels of nitrosamines, a likely carcinogen.
The drugmaker said Aug. 16 that the drugs contain the nitrosamine N-nitroso-varenicline above acceptable levels.
Long-term intake of N-nitroso-varenicline may be associated with a theoretical potential increased cancer risk, but there's no immediate risk to patients taking the drug, Pfizer said. The health benefits of stopping smoking outweigh the potential risk from the drug, according to the FDA.
Chantix is intended for short-term use to help people stop smoking. People who smoke cigarettes are 15 to 30 times more likely to get lung cancer than those who don't smoke, the FDA said.
Pfizer halted global distribution of Chantix in June after finding the elevated nitrosamine levels and recalled nine lots of the drug. In July, the FDA said it would allow drugmakers to sell generic versions of the drug even if they contain low levels of nitrosamines, as the health benefits of quitting smoking outweigh the risk from the drug.
Read the full news release here.