WASHINGTON — E-cigarettes were about as effective at helping people quit smoking as the gold-standard pharmaceutical drug, varenicline, according to a clinical trial published Monday in JAMA Internal Medicine.
The trial randomized 458 people who smoked daily and wanted to quit to receive either a nicotine-containing e-cigarette and placebo tablets, varenicline and an e-cigarette without nicotine, or a placebo tablet and a nicotine-free e-cigarette for 12 weeks. All three groups were also given intensive tobacco cessation counseling.
After 26 weeks, roughly equal percentages of participants using varenicline and e-cigarettes — 43.8 percent and 40.4 percent, respectively — had stopped smoking. The difference in quit rates between the two groups was not statistically significant.
The JAMA study is the first published randomized controlled trial to compare varenicline, also known as Chantix, directly to e-cigarettes. Several studies have demonstrated that e-cigarettes can help adults quit smoking. However, most studies have compared e-cigarettes to placebo alone, or to nicotine replacement therapy, such as patches and lozenges, which help smokers manage their withdrawal symptoms.
The trial is likely to cause a stir within the tobacco-control community, which has been bitterly divided over the question of whether e-cigarettes are a help or hindrance for adults who smoke cigarettes, and whether they should be recommended by doctors as a way to kick a smoking habit. While countries like the United Kingdom actively encourage smokers to use these products to help them quit cigarettes, nations including the United States and Japan have been far more conservative. Backers of e-cigarettes say this study shows the U.K. has the right idea.
“In this country and elsewhere … public health groups are working hard to limit access to [e-cigarettes], which is counterproductive to a goal of making more … stop smoking treatment options available to people who smoke,” said Kenneth Michael Cummings, a professor at the Medical University of South Carolina, and a vocal supporter of e-cigarettes as a cessation tool.
Varenicline is considered the most effective smoking cessation treatment. The pill works primarily by blocking the receptors in the brain that make nicotine pleasurable. However, the drug is associated with sometimes troubling side effects, including abnormal vivid dreams and insomnia. Availability of the drug has also been spotty, both in the United States and abroad, due to manufacturing problems.
The study was conducted in Finland and led by researchers at Lapland Central Hospital.
Independent researchers who reviewed the study said that while e-cigarettes should not replace varenicline as a first-line treatment, they should be seen as a viable option for smokers trying to quit.
“Varenicline’s long track record of efficacy and safety and its approval from FDA as a smoking cessation aid favors it as the first-line choice, but this study indicates that [e-cigarettes] are certainly an option for people who are unsuccessful with or cannot tolerate varenicline,” said Nancy Rigotti, director of the Tobacco Research and Treatment Center at Massachusetts General Hospital, who was not involved in the study.
Not everyone is convinced that this new study should change the United States’ approach toward e-cigarettes, especially given outstanding questions about their impact on users’ long-term health.
“The big limitation of the paper is that it assumes that e-cigs are so much safer than [cigarettes] that the authors don’t need to consider any continuing use of e-cigs as a complication. This is wrong,” said Stanton Glantz, a retired professor at the University of California, San Francisco, who is critical of e-cigarettes.
The results of the study also provide hints that varenicline may still be more effective long-term for cessation compared to e-cigarettes, according to Rigotti. That’s because e-cigarettes did not maintain a statistically significant advantage over placebo during a 52-week follow up, while varenicline did maintain its advantage. The difference between varenicline and e-cigarettes at 52 weeks was not statistically significant.
“Because the difference between [e-cigarettes] and varenicline at one year is not statistically significant (just misses), the study cannot conclude that varenicline is better, though it hints that [a] larger study might find that,” Rigotti explained.
The primary endpoint of the study was abstinence at 26 weeks, not 52. The Food and Drug Administration recommends that companies developing smoking cessation treatments assess their impact on smoking for a minimum of four weeks, though a 26-week assessment is typically considered the preferred period for a study to reliably predict long-term abstinence from cigarettes. The U.S. Preventive Services Task Force, which reviews the evidence underlying various tobacco treatments, for example, judges an intervention’s efficacy based on how well it keeps smokers abstinent for at least six months.
It’s also unclear how the results of the study published Monday would differ if participants were given different types of e-cigarettes. The newly published study used a vape loaded with a relatively low concentration of nicotine compared to a number of vapes currently on the U.S. market.
There are reportedly more than 9,000 e-cigarette products on the shelves in the United States ranging in nicotine concentration. Research has also found that vapes vary dramatically in how well they deliver nicotine to the user. No e-cigarette has been approved as a smoking cessation device in the United States.
The cessation counseling offered to each participant in the new trial may have also influenced quit rates. One out of five participants given the placebo drug and device successfully quit smoking after just receiving counseling, which the authors note “seems to indicate that repeated [counseling] may help at least some of these confirmed adults who smoke to quit the habit.”