An experimental smoking-cessation drug increases the odds that smokers can kick the habit compared with a widely used drug now on the market, researchers say.

In new studies, 44 percent of smokers taking varenicline were able to stop lighting up. In contrast, just 30 percent of those taking the already-approved Zyban and 18 percent of those who took a placebo were able to quit.

And by a year later, 23 percent of people taking varenicline were still off the cigarettes vs. 15 percent on Zyban.

“Varenicline is not just another tool, but a better tool, to quit smoking,” says researcher Serena Tonstad, MD, PhD. Tonstad is a professor of nutrition at the Universityof Oslo and an attending physician in the department of preventive cardiology at Ulleval University Hospital in Oslo, Norway.

The new drug packs a one-two punch against the deadly addiction, she tells WebMD.

First, it attaches to nicotine receptors in the brain. “This prevents the release of dopamine, a brain chemical that makes people feel rewarded, and as a result they don’t want more nicotine,” Tonstad says.

But it also activates the nicotine receptors, “so you don’t get as many cravings or withdrawal symptoms,” she says.

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Never Too Late to Quit

The two new studies, presented here at the annual meeting of the American Heart Association, included about 2,000 smokers who were randomly assigned to receive varenicline, Zyban, or a placebo. None of the participants knew which pill they were taking.

In a third study of 1,206 smokers who knew they were taking varenicline, 44 percent were still smoke-free a year later, compared with 37 percent of those who received a placebo.

Knowing they were getting a smoke aid may have helped more people fight the urge to pick up, Tonstad says.

Timothy Gardner, MD, a heart surgeon at Christiana Care Health Services in Wilmington, Del., says new ways to fight the addiction are sorely needed. On average, men who smoke die 13.2 years earlier than men who do not smoke, and women who smoke die 14.5 years earlier than women who do not smoke, according to the U.S. Surgeon General’s Health Consequences of Smoking report from 2004.

“It’s never too late,” he tells WebMD. According to the World Health Organization, a smoker’s risk of developing heart disease drops by 50 percent within one year of quitting. Within 15 years, the

Quit Smoking: Your Guide to Kicking the Habit

By Charlene Laino, reviewed by Louise Chang, MD

SOURCES: American Heart Association Scientific Sessions 2005, Dallas, Nov. 13-16, 2005. Serena Tonstad, MD, PhD, professor of nutrition, Universityof Oslo; attending physician, department of preventive cardiology, Ulleval University Hospital, Oslo, Norway. Timothy Gardner, MD, chairman, American Heart Association Committee on Scientific Sessions Program; medical director, Center for Heart and Vascular Health, Christiana Care Health Services, Wilmington, Del.