The smoking-cessation drug, Chantix, did not show benefits over other cessation aids, like nicotine patches and lozenges, at helping people quit, according to a recent study in JAMA.
Chantix (varenicline), manufactured by Pfizer, was approved by the FDA in 2006.
Results of the three approaches did not differ statistically at either six months or a year, the researchers found. At six months, the rate of quitting was 23 percent for the patch; 24 percent for Chantix; and 27 percent for a combination of patch and lozenges. At a year, the quit rate was 21 percent, 19 and 20 percent, respectively, according to the study.
“To our surprise, all three treatments were essentially identical,” said lead author Dr. Michael Fiore, director of the University of Wisconsin Center for Tobacco Research and Intervention in Madison.
Chantix or a combination of the nicotine patch and lozenges were previously shown in studies to be more effective than the patch alone, “but no one had compared them,” said Fiore in a HealthDay article.
The JAMA study followed more than 1,000 smokers, who at the start of the study were around 48 years old and had been smokers for about two decades. They smoked on average 17 cigarettes a day.
After 26 weeks, the researchers confirmed whether or not they had refrained from smoking by using lab tests to see if the levels of carbon monoxide in their breath were low.
Side effects were more common in people who used Chantix, with about 29 percent of people reporting nausea, 23 percent reporting vivid dreams and 22 percent reporting insomnia. Chantix has a black-box warning about side effects associated with the drug — the drug’s been linked with psychiatric risks, including seizures, and aggressiveness and blacking out when people drink while taking the drug. Additional side effects associated with Chantix include suicidal thoughts, hostility and agitation.
Side effects associated with the patch included itching, vivid dreams and insomnia, while side effects with combined patch and lozenge use were itching, nausea and vivid dreams.
Pfizer said in a statement that the results of the study are inconsistent with findings from previous research that reported “superior efficacy of varenicline (Chantix) and combination therapy, compared with nicotine-replacement therapy alone.” The company added that a best trial type would include receiving Chantix, or nicotine-replacement therapy or a placebo, but not know which.
The study authors acknowledge a shortcoming of the study: more than half of the patients in each treatment group stopped therapy before the 12-week regimen was completed.
The reasons for why the treatments worked equally well are not known, said Fiore. “A person’s desire to quit is really powerful. The treatments are important and boost quit rates, but that in no way discounts the incredibly powerful influence of a person’s commitment to change behavior.”
The study was supported by the U.S. National Heart, Lung, and Blood Institute.
Filed Under: Drug Discovery