A number of consumer complaints about mental and behavioral side effects of Chantix have led the FDA to require that a new black box warning be placed on the stop-smoking medication, alerting users that the drug may cause suicidal tendencies.
Chantix (varenicline), which is manufactured and sold by Pfizer, was approved by the FDA in 2006 and was quickly recognized as a potential blockbuster. It works by blocking the receptors in the brain that are commonly stimulated by nicotine, reducing the positive feelings that come from cigarettes. However, hundreds of users have reported severe psychological side effects, such as depression, sudden aggressive behavior and suicide from Chantix.
After initiating a review of the Chantix suicide problems in November 2007, the FDA announced on Wednesday that the most stringent warning allowed under federal regulations will be placed on the medication. A boxed warning will notify consumers that the smoking cessation drug may increase the risk of changes in behavior, depression, hostility and suicidal thoughts.
The same warning was also required for bupropion-based medications, including another smoking cessation drug Zyban, the antidepressant Wellbutrin, as well as bupropion generics, many of which carry suicide warnings already.
Although Chantix already contains information on their label about reports of suicide, unusual behavior and other psychological side effects, the new warning will contain far more direct language and will be displayed prominently on the label in a black box.
In addition to the warning, the manufacturers of these drugs are required to conduct clinical trials to provide more data on how often the neuropsychiatric symptoms occur and under what conditions. They will also have to add more information in the medication guide that discusses the risks of the potential behavioral and mental changes, so that patients are aware to immediately contact their doctor if they notice any behavioral changes.
A number of Chantix lawsuits have been filed against Pfizer alleging that the drug maker failed to properly research their medication or adequately warn about the potential suicide risk with Chantix. During clinical trials before the approval of Chantix, individuals with a psychiatric history or current psychiatric symptoms were excluded from the study, even though many people with depression or other forms of psychiatric illness are smokers who used the drug to help themselves quit.
The new warnings will ensure that potential users are aware of the problems that may be caused by using the medication to help them quit smoking. The FDA notes that people should seriously weigh the potential risk of suicide with Chantix and Zyban before deciding to use either of the drugs.
“The risk of serious adverse events while taking these products must be weighed against the significant health benefits of quitting smoking,” said Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research. “Smoking is the leading cause of preventable disease, disability, and death in the United States and we know these products are effective aids in helping people quit.”