Federal drug regulators announced that they will temporarily allow manufacturers to distribute the anti-smoking drug varenicline with elevated levels of an impurity that may cause cancer, to maintain availability after Pfizer halted distribution of its Chantix branded varenicline.

Pfizer in June halted distribution of Chantix and recalled a number of lots after finding elevated levels of nitrosamines in the pills.

On Friday, it recalled 12 more lots.

The Food and Drug Administration (FDA) will temporarily allow some manufacturers to distribute varenicline containing impurities above its intake limit of 37 nanograms per day, but below an interim limit of 185 ng per day, until the impurity can be eliminated or reduced to acceptable levels.

Get the full story at reuters.com.