Chantix may also lead to a heart attack or stroke, since a September 2006 study found that one in twenty Chantix users will experience a heart attack, stroke, or other cardiovascular problem. Other research also links the drug to cardiovascular disease.
Some Chantix users have reported less severe side effects, such as mild depression, constipation, gas, and nausea. Sleep disorders, abnormal dreams, and vomiting have also been reported.
Plaintiffs in Chantix lawsuits charge that they were not warned about the risk of the side effects.