In clinical trials, Pfizer Inc.'s anti-smoking drug Chantix shows that it may produce a higher rate of heart attacks or strokes in patients using the treatment than those who did not use the treatment. Today, the U.S. Food and Drug Administration posted a safety notice on its website. According to the agency, the increased risk was not statistically significant, but it is most likely Chantix related. Currently, Chantix has a warning that increases risks of suicide. The warning also states that the drug may be tied to increased heart danger in patients who already have cardiovascular disease. Pfizer was asked to reevaluate the risks using a large analysis of existing studies on the drug. The FDA's announcement is based on the additional analysis Pfizer did. In the trials, of the 4,190 Chantix users, 13 had a major cardiovascular event. Of the 2,812 who took a placebo, instead of Chantix, 6 had a major cardiovascular event. Pfizer is formally stating that the benefits of Chantix outweigh the risks.