The latest debates about Chantix (Varenicline), a prescription medication used to treat smoking addiction, caused by possible negative consequences made its manufacturer, Pfizer, expand the list of warnings.
Now it includes information that taking this drug should be observed for serious neuropsychiatric symptoms, such as: agitation, changes in behavior, depressed mood, suicidal ideation and suicidal behavior.
Chantix is the first approved nicotinic receptor partial agonist. It both reduces cravings for and decreases the pleasurable effects of cigarettes and other tobacco products, and through these mechanisms, it can assist some patients in quitting smoking.
In May 2006, it was approved for sale in the United States. On August 1, 2006, Pfizer announced that Chantix was available for sale in the United States, and on September 29, 2006 , it was approved for sale in the European Union.
In November 2007, the FDA announced it had received post-marketing reports that patients using Chantix for smoking cessation had experienced several serious symptoms, including suicidal ideation and occasional suicidal behavior, erratic behavior, and drowsiness. It is unknown whether the psychiatric symptoms are related to the drug or to nicotine withdrawal symptoms, although not all patients had stopped smoking. FDA is aware of a highly-publicized case of Carter Albrecht who was shot to death by his neighbor after, in the apparent state of delirium, hitting his girlfriend and trying to force the entry in the neighbor's house. Although in this case the delirium appeared to be caused by taking varenicline with a high dose of alcohol, FDA asked Pfizer for additional cases that might be similar. The FDA also recommended that health care professionals and patients watch for behavioral and mood changes.