FDA: Seizure, Alcohol Risk with Pfizer’s Chantix

The U.S. Food and Drug Administration (FDA) has determined it will not reduce the severity of its black-box warning about side effects associated with Pfizer’s Chantix, reports Reuters. The smoking-cessation drug has been linked with psychiatric risks, including seizures, and aggressiveness and blacking out when patients drink while taking the drug.

Chantix, known chemically as varenicline, was approved in 2006. The FDA soon after updated the warning label to include side effects such as suicidal thoughts, hostility and agitation.

Pfizer has requested the FDA remove the black box, the most serious safety alert that can appear on product labeling. Although Pfizer has said its own studies do not support an association between Chantix and such severe side effects, an FDA advisory committee in October 2014 recommended leaving the black box alone awaiting the outcome of an ongoing safety study.

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Since then, the FDA has examined data, including Pfizer’s, and determined that these observational studies were limited. Pfizer is working on another safety study on the drug, and trial results are expected in late 2015.

In the meantime, the FDA said it will keep the black-box warning.

Sales of Chantix fell last year to $647 million from $846 million in 2008, and Pfizer spent hundreds of millions of dollars to settle lawsuits in the last several years, The Wall Street Journal’s Pharmalot blog reports.