Pfizer's smoking-cessation drug Chantix induced manic, violent psychosis requiring hospitalization, a man claims in Federal Court. He claims Pfizer failed to warn about the side effects, which have "caused serious injury and death."

Chantix is supposed to work by inhibiting nicotine receptors in the brain. Those receptors are controlled by dopamine, a neurotransmitter, the complaint states: "Essentially, Chantix regulates/restricts dopamine and blocks pleasure sensors to depress the normal flux of emotions experiences by humans in daily life."

Brian Kline claims Pfizer concealed and misrepresented the risks of Chantix (varenicline), knew that it was unsafe and had "caused serious injury and death," but failed to warn of it. He claims he took the drug, "which caused the plaintiff to sustain injuries and damages including but not limited to manic behavior, aggressive and violent behavior and diagnosis of psychotic disorder for which the plaintiff was hospitalized in August 2007.

Kline claims Pfizer intentionally excluded from its clinical trials people with histories of depression or psychological disorders. He claims that Chantix is derived from cytosine, and that Pfizer knew or should have known that cytosine was linked as early as 1972 to suicides and attempted suicides.

Kline demands punitive damages. He is represented by Scott Levensten