The U.S. Food and Drug Administration (FDA) issued an alert Feb. 1, 2008, to highlight important revisions to the warnings and precautions sections of the full prescribing information for Chantix (generic name varencicline) regarding serious neuropsychiatric symptoms.
The anti-smoking medication manufactured by Pfizer and marketed under the name Chantix has been under investigation since November 2006 after patients taking the twice-daily pill reported depression, agitation and suicidal thoughts and behavior.
According to the FDA, a direct link between Chantix and the reported psychiatric problems has not been established, but cannot be ruled out. The FDA recommends that patients using Chantix or considering it should talk with their physician about any history of mental illness. “As FDA’s review of the issue has progressed, it appears increasingly likely that there is an association between Chantix and serious neuropsychiatric symptoms,” the alert reads.
Those already taking Chantix also should use caution when considering stopping its use, the FDA alert advises. “In most cases, neuropsychiatric symptoms developed during Chantix treatment, but in others, symptoms developed following withdrawal of Chantix therapy,” the alert reads.
The FDA requested that Pfizer elevate the prominence of FDA safety information to the “Warnings” and “Precautions” sections of the Chantix prescribing information, and is working with Pfizer to finalize a Medication Guide for patients.
Chantix has already been prescribed to 4 million people in the U.S. since its FDA approval in May 2006, according to Pfizer. The Associated Press reports that for full-year 2007, the drug had sales of $883 million. The medicine works by binding to nicotine receptors in the brain, reducing the symptoms of withdrawal.