The U.S. Food and Drug Administration has issued a new warning about the drug Chantix, which is designed to help smokers quit smoking.
The FDA and Chantix manufacturer Pfizer have received complaints from patients of seizures, blackouts and increased aggressive behavior after mixing Chantix with alcohol, according to the L.A. Times.
"Until patients know how Chantix affects their ability to tolerate alcohol, they should decrease the amount of alcohol they drink," the FDA said, adding that some of the patients who experienced seizures had seizure disorders, but others did not. The agency has added these side effects to the "Warnings and Precautions" label to Chantix.
Chantix was approved in 2006, Fox News reported. The FDA updated the label to include a warning about neuropsychiatric side effects such as suicidal thoughts, hostility and agitation. A black box appears on the Chantix label, and boxed warnings are for the most serious risks.
Pfizer has asked the FDA to remove the black box citing their own studies that claim there is no association between Chantix and psychiatric side effects. In October, an FDA advisory committee said they wanted to keep the black boxes pending the outcome of a safety study. The FDA has said that they will keep the black boxes until they receive the results of the trial.
About 1.2 million people filled Chantix prescriptions in 2013, the L.A. Times reported. Chantix, whose generic name is varenicline, stops the nicotine in cigarettes from stimulating the nicotine receptors in the brain. If an individual relapses, the experience of smoking will not be satisfying. In addition, Chantix prompts the brain to release small amounts of dopamine, which makes nicotine withdrawal easier.
Common side effects of Chantix include nausea, trouble sleeping and gastrointestinal problems like gas and constipation. The FDA has received 11 reports of decreased alcohol tolerance, 37 reports of aggressive behavior and 64 cases of seizures. Pfizer is conducting a clinical trial to find some answers.
Results of the trial are expected in late 2015, according to Fox News. Pfizer earned $647 million in revenue from Chantix prescriptions.