Chantix Heart Risks Questioned by Pfizer

Pfizer Inc. is questioning the validity of a recent study that suggests Chantix increases the risk of heart problems, seemingly dismissing concerns raised about the potential side effects of the stop-smoking drug. 

In a statement released this week, Pfizer criticized the findings of a study published Monday in the Canadian Medical Association Journal, maintaining that current safety data involving more than 7,000 people has found no evidence of heart side effects for Chantix. The company suggests that the recent findings could be inaccurate due to the overall low number of heart events found in the study.

Researchers mined a number of databases for double-blind, randomized controlled trials involving people who took Chantix and were later found to have suffered a cardiovascular event, including heart attacks. They found that side effects of Chantix may substantially increase the risk of heart attacks, strokes and other cardiovascular problems by 72% over smokers who did not take the drug.

Despite the limitations of the study, the senior author of the study was quoted by the New York Times suggesting that the findings are disturbing enough that the FDA should consider issuing a Chantix recall. When added to prior research that has linked Chantix use to violent behavior, suicidal tendencies and other psychological side effects, the study’s authors suggested that the drug’s benefits may be outweighed by its side effects.

Pfizer officials indicate that they are in talks with the FDA about conducting additional trials to better study the heart risks of Chantix. However, critics are questioning why the drug maker did not adequately follow up on the initial safety signals regarding cardiovascular problems associated with the popular smoking cessation drug.

Chantix (varenicline) was approved in the United States by the FDA in 2006 as a prescription medication to help people quit smoking. The drug works by reducing the positive feelings that come from cigarettes, blocking the receptors in the brain commonly stimulated by nicotine.

Last month, the FDA issued a drug safety communication about the potential risk of heart problems from Chantix, warning that the smoking cessation drug might increase the risk of certain cardiovascular events, including the risk of heart attack, among individuals who had cardiovascular disease. However, the new study published this week found that even those without a history of heart disease may also face a significant risk.

Chantix holds the dubious title of being the drug associated with the most FDA adverse event reports of any prescription medication in the United States, including powerful painkillers and other drugs used to treat more serious conditions. More patients and doctors call or write the agency to complain about Chantix health problems than any other drug currently on the market by a wide margin.

Pfizer already faces a number of Chantix lawsuits that have been filed on behalf of individuals who have died or suffered serious injuries as a result of a suicide or unusual behavior allegedly caused by psychological side effects of Chantix. In recent weeks, many lawyers have begun reviewing the potential for Chantix heart lawsuits as well, alleging that the drug maker failed to adequately research the medication before heavily promoting it as a way to help people stop smoking and improve their health.