Pfizer’s smoking cessation drug, which has already been linked to psychiatric side effects, can lead to a small increase in heart problems in people with cardiovascular disease, the Food and Drug Administration (FDA) said yesterday.

The new warning is based on a 700-person clinical trial that determined patients who took Chantix (varenicline) over 12 weeks were more likely to experience an adverse heart event after one year than those who received a placebo. All of the patients were previously diagnosed with heart disease. 
Chantix, usually in the form of varenicline tartrate, is a prescription medication used to treat smoking addiction. The FDA requires Chantix to carry a black box warning, the agency’s strongest safety warning, due to public reports of side effects including depression, suicidal thoughts and suicidal actions. (pi)