Anti-Smoking Drug Raises Risk of Heart Problems

(National Institute of Mental Health)

Researchers at Johns Hopkins University, Wake Forest University, and University of East Anglia in the U.K. found healthy tobacco users that take a leading smoking cessation drug face a notably greater chance of hospitalization from heart problems, compared to those taking a placebo. The findings appear in the current issue of the Canadian Medical Association Journal.

The team, led by Sonal Singh of Johns Hopkins, reviewed and analyzed 14 double-blind, randomized, controlled clinical trials involving more than 8,200 healthy people who received either varenicline — made by Pfizer and sold in the United States under the brand-name Chantix — or a placebo. The studies selected were at least one week in length and involved smokers or people who used smokeless tobacco that reported on cardiovascular events, including ischemia, arrhythmia, congestive heart failure, sudden death, or cardiovascular-related death as serious adverse events associated with the use of varenicline.

The researchers found that the same number of people — seven — died in each group; numbers too small to allow meaningful comparisons of mortality. But the increased risk of a major harmful cardiovascular event requiring hospitalization such as a heart attack or arrhythmia was 72 percent in the groups taking varenicline.

None of the studies followed people for longer than a year. The average age of study participants was less than 45 years and the majority were men.

On 16 June, the Food and Drug Administration noted that the drug may be associated with a small, increased risk of certain cardiovascular adverse events in patients who have cardiovascular disease. FDA based its recommendation on a  randomized, double-blind, placebo-controlled clinical trial of 700 smokers with cardiovascular disease who were treated with varenicline or placebo. Varenicline already carried a warning about changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts while taking the drug.

Read more: Drug in Development Targeting Nicotine Metabolism

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