July 27, 2010 -- Evidence is accumulating that the stop-smoking drug Chantix is linked with unprovoked acts and thoughts of aggression and violence, according to a new report.
The drug is so potentially dangerous that its use should be restricted to exclude police, military, and similar occupations in which workers carry weapons, says Thomas J. Moore, senior scientist for drug safety and policy at the Institute for Safe Medication Practices, a nonprofit watchdog group. Moore is one of three co-authors of the new report on the drug, published in the Annals of Pharmacotherapy.
"My colleagues and I have been concerned about the safety profile of [Chantix] since our first report [warning of adverse events] in 2008," Moore tells WebMD.
But others, including a smoking cessation researcher and a spokesperson for Pfizer, which makes Chantix, disagreed strongly. They point out that the number of adverse events is far outweighed by the benefits of the drug, which has helped countless people give up cigarettes and the health risks associated with tobacco use.
One co-author of the report, Joseph Glenmullen, MD, of Harvard Medical School, has been retained as a potential consultant in legal cases involving Chantix. He often provides expert testimony on the side effects of psychiatric medications.
Chantix was approved by the FDA in May 2006 as a smoking cessation treatment. It targets nicotine receptors in the brain, blocking nicotine from getting to them.
Smokers begin at a low dose and then increase it, continuing to smoke until the eighth day, when they are instructed to quit. They continue the drug for 12 weeks and in some cases an additional 12.
In late 2007, concern surfaced after an episode in which a Dallas musician taking the drug displayed aggressive, abusive behavior and was shot dead while trying to kick in the door of a girlfriend's neighbor, the researchers write.
Since the drug came on the market, the FDA has received adverse event reports and then issued communication about the possible risks, and required a medication guide be given to each patient and with each refill. On the package insert, a boxed warning says that some people have had changes in behavior as well as hostility, agitation, suicidal thoughts, and other problems. Patients are advised to stop the drug and get medical help if that happens.
Chantix: A Closer Look
Moore and his colleagues gathered information on 78 adverse event reports received by the FDA as well as four other cases reported in clinical trials and three others from published literature. Moore suspects that the 78 cases are just a fraction of existing reports and that some adverse events are unreported.
The researchers used assessment tools to home in on 26 of the cases to look at more closely. Of these 26:
10 involved assault
9 involved homicidal thoughts
7 cases included other thoughts or acts of aggression or violence