Chantix has helped many people quit smoking in the years since its release.  However, on Monday the U.S. Food and Drug Administration issued a warning about the quit-smoking drug made by Pfizer Inc.  According to the FDA, the drug has been associated with seizures and that some patients who drink while taking the drug may become aggressive or even black out.

The FDA stated that it approved an update to the drug's label in September but issued the notice to the public to ensure patients are aware of the changes "and can consider this new information when making prescribing decisions."  Typically, these types of warnings are issued at the time of the label change.

"Until patients know how Chantix affects their ability to tolerate alcohol, they should decrease the amount of alcohol they drink. Patients who have a seizure while taking Chantix should stop the medicine and seek medical attention immediately," the FDA warned in a release.

Varenicline, otherwise known as Chantix, was approved for use in 2006.  The FDA has since updated the label to include a warning, highlighted by a black box, of neuropsychiatric side effects, including suicidal thoughts, hostility and agitation.

The black box warnings are reserved only for the most serious of risks in drugs.  Pfizer has since asked the FDA to remove the black box, saying that its own studies show no association between the drug and severe psychiatric side effects.  However, an FDA advisory committee in October recommended the black box label remain pending the outcome of an ongoing safety study.

The FDA stated on Monday that it had examined many different studies of the drug and its side effects, including various studies conducted by Pfizer.  However, in many cases, the studies had limitations that prevented the agency for drawing any type of reliable conclusions about the safety of the drug, Chantix. 

The company is currently conducting an additional safety study of its own of the drug with the results of the trial expected something in late 2015.  Until the completion of the trial, the FDA has stated that it plans to keep the black box in place to ensure safety of patients taking the drug.

Chantix has helped thousands of people quit smoking and continues to rise in popularity as more and more smokers look to kick to the habit.  In 2014 alone, the drug generated $647 million in revenue for Pfizer and continues to soar in popularity as a means of quitting smoking.