Smoking cessation: the medium-term effectiveness of varenicline demonstrated in three studies

Three studies published in the "Journal of the American Medical Association" demonstrate the value of varenicline (Chantix * Pfizer) in smoking cessation, this molecule gives better results than placebo and bupropion (Zyban * GlaxoSmithKline ).

The U.S. drug regulatory agency, the Food and Drug Administration (FDA) has authorized the placing on the U.S. market * Chantix (varenicline, Pfizer) in smoking cessation.

"* Chantix acts on areas of the brain affected by nicotine and may help those who want to quit smoking in two ways: by providing some nicotine effects to ease the withdrawal symptoms and by blocking the effects of nicotine cigarettes if they resume smoking, "the FDA explained in a statement.

U.S. approval of Chantix * is based on the results of six clinical trials involving 3,659 chronic smokers treated with varenicline. Three of them are published in Jama.

The first two show that taking varenicline for twelve weeks is associated with a smoking cessation rate of 44%, against 17.7% with placebo and 29.5% with bupropion. Over a longer period, from the 9th week of treatment at week 24 of follow-up, abstinence rates with varenicline remains higher, reaching 29.5% (29.7% in the second study), against 10 5% (13.2%) with placebo and 20.7% (20.2%) with bupropion. Finally, on a more long-term, up to the 52nd week of monitoring these numbers are respectively 21.9% (23%), 8.4% (10.3%) and 16.1% (14, 6%).

David Gonzales, who led the first study at the University of Science and Medicine in Portland, Oregon, and Douglas E. Jorenby, who led the work at the Faculty of Medicine and Public Health at the University of Wisconsin at Madison, enter both the effectiveness of varenicline in smoking cessation, and the superiority of this molecule compared to bupropion.

In the third study published in the American medical journal, Serena Tonstad of Ulleval University Hospital in Oslo (Norway) for its assessed value of varenicline in preventing relapse in people who have successfully quit smoking after twelve weeks of treatment.

According to the results, the rate of continuous abstinence achieved with varenicline were higher than those obtained with placebo, however is mitigated over time (70.5% against 49.6% of the week 13 to 24, and 43.6% against 36.9% in week 13 to 52).

Moreover, at the end of the study, as in all that included a year of monitoring, more than half of participants in each group took over the cigarette. The authors therefore consider it necessary to evaluate the effectiveness of varenicline relapse prevention over a longer period.

In an editorial, three specialists temper the enthusiasm of researchers, clinicians and especially that which can now use varenicline since its introduction on the market. Robert C. Klesges, Karen C. Johnson and Grant Somes, University of Tennessee at Memphis, in fact believe that "varenicline is certainly not a panacea for smoking cessation. Several participants experienced side effects, discontinued treatment or stopped attending school. Importantly, the majority of participants in these three studies have failed to quit smoking even with varenicline, "they said.

According to them, "stop smoking, even with pharmacological and behavioral assistance is extremely difficult. Patients can not, and probably can never simply take a drug that will help them to quit smoking. Smokers must want s' stop and must be willing to work hard to achieve it, "they write.