March 9, 2015
The updated Warning and Precautions section of the label is based on a case series submitted by Pfizer and cases in the FDA Adverse Event Reporting System (FAERS) database, which describe patients who consumed alcohol during varenicline treatment and experienced adverse reactions including decreased tolerance to alcohol, unusual or aggressive behavior, or no memory of past events.
A review of FAERS and the medical literature also identified cases of seizures with varenicline treatment in patients with no history of seizures or a seizure disorder that had been well-controlled. These seizures occurred within the first month of varenicline therapy in most cases.
The labeling will also include information on several studies investigating the risk of neuropsychiatric side effects on mood, behavior, or thinking occurring with varenicline. While these studies did not show an increased risk of neuropsychiatric side effects with varenicline, they did not examine all types of neuropsychiatric side effects and had limitations that prevented the FDA from drawing reliable conclusions. Pfizer is currently conducting a large clinical safety trial to investigate the risk and the study results are expected in late 2015.