Chantix Linked to Violence and Aggressive Behavior in New Study

The findings of a new study seem to confirm the link between side effects of Chantix and violent behavior. Pfizer’s blockbuster smoking cessation drug has previously been linked to an increased risk of suicide and other psychiatric side effects, but this is the first to specifically examine reports of violence and aggression.

Researchers from the Institute for Safe Medication Practices published a report in the current issue of the medical journal The Annals of Pharmacotherapy, providing evidence that the use of Chantix is linked to aggressive and violent behavior, which could result in a serious injury for the user or those around them.

Chantix (varenicline) was approved in the United States by the FDA in 2006 as a prescription medication to help people quit smoking. The drug works by reducing the positive feelings that come from cigarettes, blocking the receptors in the brain commonly stimulated by nicotine. However, the impact of the drug on the brain has resulted in a number of reports from users who experienced sudden, unusually aggressive behavior, thoughts of self-harm and suicide.

In June 2009, a “black box” warning was added to the medication about the potential risk of problems with Chantix, indicating that some users have experienced changes in behavior, depression and suicidal thoughts. Pfizer has also been required to conduct clinical trials providing more data on how often neuropsychiatric symptoms and suicide with Chantix occur and what conditions cause them.

The new study looked specifically at violent or aggressive acts or behaviors, which were not included as part of the prior warnings. Researchers studied 78 Chantix adverse event reports submitted to FDA through its MedWatch database, as well as seven other cases from other sources. They said they found several common characteristics among cases where Chantix appeared to be linked to violence or aggression.

Scientists found that the acts of violence were inexplicable and unprovoked, the Chantix users victimized anyone nearby, there was no prior indication of similar behavior and the psychiatric side effects occurred quickly; often before they had gotten to the point in their Chantix use where they had stopped smoking. Researchers found that violent and aggressive behavior ended for 93% of the subjects when they stopped taking Chantix.

In one case examined by the researchers, a 47-year-old woman who had taken Chantix for a month started assaulting her daughters and yelling at them before committing suicide by shooting herself. In another case, a man who had been taking Chantix for eight days choked his wife in a fit of rage and then hung himself. Less extreme cases include people who suddenly woke up and assaulted the person closest to them, started fights and destroyed property, often their own.

The researchers said that while there has been plenty of attention paid to Chantix suicide problems, more attention needs to be brought to the violence and aggression side effects of Chantix as well. They recommended that doctors do more to warn patients about the risk of Chantix violent behavior and that patients immediately report any strange and uncharacteristic violent urges while taking the drug.

Lawsuits over Chantix have been filed in state and federal courts throughout the United States on behalf of individuals who have suffered injuries from the neuropsychiatric side effects of Chantix, skin reactions from Chantix and for family members of individuals who have committed suicide on Chantix.

In October 2009, the U.S. Judicial Panel on Multidistrict Litigation consolidated all federal Chantix lawsuits in the U.S. District Court for the Northern District of Alabama. According to a pretrial scheduling order issued earlier this year, the first Chantix trial is unlikely to reach a jury until at least 2012.