FDA Allows Chantix Generics With High Levels of Nitrosamines

The FDA said it will temporarily allow distribution of generics of Pfizer’s smoking cessation drug, Chantix (varenicline), even though they may contain more than the acceptable daily limit of a potential carcinogen — to ensure an adequate U.S. supply “for the near term.”

Pfizer suspended worldwide distribution of the drug last month after elevated levels of the suspected carcinogen, nitrosamine, were found in some batches of the pills.

The agency said it will “exercise regulatory flexibility and discretion” to allow Apotex — which currently distributes varenicline in Canada — to distribute its Apo-Varenicline tablets in the U.S.

The temporary approval covers tablets containing N-nitroso-varenicline above the agency’s acceptable intake limit of 37 nanograms per day but below the interim acceptable intake limit of 185 nanograms per day until the impurity “can be eliminated or reduced to acceptable levels.”