Varenicline Helps in Gradual Smoking Reduction

Clinical guidelines from the Agency for Healthcare Research and Quality recommend promoting smoking-cessation aids that will help cigarette users quit smoking abruptly, though research suggests that 44 percent of cigarette smokers prefer to quit through a more-gradual approach such as a reduction in the number of cigarettes—implying that more-effective therapies are needed to meet the demands of some patients seeking abstinence from smoking.

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To address the preferences of these smokers, researchers from the Mayo Clinic Nicotine Dependence Center conducted a large-scale study to determine the efficacy and safety of the smoking-cessation drug varenicline in increasing smoking abstinence rates through gradual smoking reduction.

“This study is important because it opens the door to treatment for approximately 14 million smokers who have no intention of quitting in the next 30 days but are willing to reduce their smoking rate while working toward a quit attempt,” said lead author Jon Ebbert, M.D., a professor of medicine and researcher in tobacco cessation. “In the past, these smokers may have not received medication therapy, and we want them to know that different approaches are available.”

According to the researchers, prior studies of pharmacotherapy-aided reduction have examined nicotine-replacement therapies that deliver nicotine through methods independent of tobacco, such as a skin-adhesive patch or chewing gum. Varenicline is a nicotine receptor partial agonist and key ingredient in the smoking-cessation drug Chantix (Psychiatric News, October 10, 2013). Recent studies have shown varenicline to be efficacious in increasing smoking abstinence rates in those cigarette users seeking to quit smoking abruptly, but the current study is one of the first, the researchers noted, to investigate the pharmacotherapy’s effectiveness in those seeking a gradual method for smoking cessation.

Ebbert and colleagues randomly assigned 1,510 cigarette smokers to receive 1 mg of varenicline or placebo for 24 weeks. They recruited smokers who were not willing or able to quit smoking within the next 30 days but willing to reduce smoking and make an attempt to quit such behavior within the following three months.

The results, published in the Journal of the American Medical Association, showed that 32 percent of the varenicline cohort achieved continuous abstinence during weeks 15 through 24, compared with 6.9 percent in the placebo cohort. In addition, the researchers observed that individuals in the varenicline group were three times more likely than the placebo group to maintain abstinence six months after treatment. Rate of serious adverse events did not differ statistically among the cohorts.

“Smokers should know that varenicline can help them quit smoking if they want to reduce their smoking prior to completely stopping,” said Ebbert. “It’s an effective and safe way to increase long-term smoking cessation.”

The researchers speculated that “the mechanism of varenicline action as an aid to gradual cessation could relate to a reduction in cigarette craving or a blockade of the reinforcing action of nicotine through partial agonist activity at the nicotine receptors,” subsequently giving patients the confidence to quit smoking.

The researchers concluded that though guidelines from the U.S. Public Health Service and others recommend abrupt abstinence from cigarette use with smoking-cessation aids, the current varenicline-based approach allows clinicians to choose from more therapeutic options when caring for patients who are seeking to slowly wean themselves from smoking.

The study was funded by Pfizer, which manufactures the Chantix brand of varenicline. ■