In our last post, we discussed a recent pharmaceutical liability lawsuit filed against drugmaker Pfizer Inc. and its California distributor. Several users of Pfizer's smoking cessation drug Chantix allege that Pfizer failed to warn them that the drug could cause a variety of mental disorders, including depression, aggression and suicide.

The most recent Chantix lawsuit alleges that Chantix is no more effective than a placebo or nicotine patch in helping individuals quit smoking. The plaintiffs allege that even if the drug were effective, the risks associated with it would outweigh its benefits.

Chantix was released in 2006 and supported by impressive studies indicating that the drug was effective and safe to use. Analysis of the studies, however, indicated that study participants were carefully screened to ensure the best results and that Pfizer employees failed to report the fact that the drug caused a threefold increase in mental disorders among its users. A European Medical Agency report from 2006 found that Chantix, also known as varenicline, increases the risk of "serious adverse reactions" six times more than the competing smoking cessation drug Zyban (bupropion).

"In the fourth quarter of 2007, varenicline accounted for 988 serious injuries in the U.S. reported to the FDA, more than any other individual drug in this time period," the lawsuit says. "By comparison, the FDA received a median of five reports of serious injury for 769 different drugs in the fourth quarter. Only 35 drugs accounted for 100 or more reports."

The lawsuit goes on to allege that Pfizer officials kept denying a link between Chantix and suicide despite admitting to Congress that prior to Nov. 20, 2007, the company received 322 reports of suicidal thoughts, 37 suicide attempts and 16 suicides by Chantix users. The number of suicides jumped to 98 by July 2009. More than 4,750 serious Chantix-related psychiatric events and 188 attempted suicides were also reported to the FDA by July 2009.

Pfizer now includes warnings regarding psychiatric disorders on its Chantix website and marketing copy.

"Some people have had changes in behavior, hostility, agitation, depressed mood, suicidal thoughts or actions while using Chantix to help them quit smoking," the Pfizer notice reads. "Some people had these symptoms when they began taking Chantix, and others developed them after several weeks of treatment or after stopping Chantix."

Source: Frazier v. Pfizer, 2012 WL 750578 (Trial Pleading) Superior Court of California, L.A. County