In July 2021, Pfizer announced a voluntary recall of nine lots of its smoking cessation drug Chantix (varenicline) due to concern about nitrosamine levels in this medication. Nitrosamines are a type of impurity that can exist in pharmaceutical products and are considered possible carcinogens when they are above acceptable levels. In September 2021, Pfizer expanded the recall to all lots of 0.5 mg and 1 mg varenicline.
You’ve been exposed to nitrosamines many times and probably didn’t even know it. That’s because these compounds are common in water and foods, including cured and grilled meats, dairy products and vegetables, according to the FDA. At low levels, experts don’t believe they’re harmful.
Why is Chantix being recalled?
Nitrosamine impurities could potentially increase your risk of cancer if you consume enough over an extended period of time. As such, the FDA set limits for the daily intake of nitrosamines. Nitrosamine impurities have led to the recall of other medications, such as Zantac (ranitidine) and metformin ER.
After these previous recalls, the FDA created guidance for pharmaceutical manufacturers to detect and prevent higher-than-recommended nitrosamine levels. As part of the suggested investigation, Pfizer discovered levels of the impurity known as N-nitroso-varenicline that exceeded the acceptable daily intake limit in Chantix. That prompted Pfizer’s decision to voluntarily recall certain lots of this particular drug.
“The benefits of Chantix outweigh the very low potential risks, if any, posed by nitrosamine exposure from varenicline on top of other common sources over a lifetime,” Pfizer spokesperson Steven Danehy said in an email, according to Reuters.
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What to do if you take Chantix
Most people take Chantix for up to 12 weeks to help quit smoking (some patients take Chantix for a longer time). The medication interferes with the receptors in the brain that nicotine stimulates. If you’re in the middle of your treatment, contact your healthcare provider for guidance.
According to the FDA, you’re not at immediate risk from this medication. “An increased cancer risk would be associated with long-term use, and the health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in varenicline,” the FDA reported. The FDA recommends discussing your treatment plan with your physician. Depending on your situation, your healthcare provider may recommend a nicotine replacement therapy, or an alternative nicotine-free prescription medication such as Zyban (bupropion hydrochloride).
Because of shortages due to the recall, the FDA will not object to distribution of varenicline tablets with nitrosamine impurities greater than 37 ng per day, as long as it’s below 185 ng per day until the impurity can be eliminated or reduced to acceptable levels.
If you have concerns about nitrosamines in other medications that you may be taking, speak with your physician.