Electronic cigarettes helped wean smokers off regular cigarettes in a clinical trial – though the quit rate was essentially the same as for nicotine patches.
The trial, conducted in New Zealand, was billed as the first head-to-head comparison of e-cigarettes and nicotine patches. The results were published online Monday in the journal Lancet and presented at the European Respiratory Society's Annual Congress in Barcelona, Spain.
E-cigarettes are sometimes marketed as smoking-cessation devices, though the U.S. Food and Drug Administration warns consumers that they have not been approved for that purpose. The battery-powered cylinders are used with cartridges that may contain low doses of nicotine. (They may also contain flavorings like mint, fruit or chocolate, as well as toxic chemicals, some of which may cause cancer, according to a 2009 report by the FDA.)
Quitting smoking appears to be one of the primary reasons people buy electronic cigarettes: One survey in Britain found that 27% of smokers who were trying to quit used e-cigarettes for that purpose.
There's good reason to think they would work at least as well as nicotine replacement patches. As the researchers behind the clinical trial noted, both patches and e-cigarettes can help smokers get through their nicotine withdrawal.
They tested that theory on adult smokers who had smoked at least 10 cigarettes a day for the previous year. In order to be enrolled in the clinical trial, smokers had to be motivated to quit.
The researchers assigned 292 volunteers to use e-cigarettes with cartridges containing nicotine and another 73 to use the devices with cartridges that didn't have nicotine. (Subjects who got e-cigarettes didn't know which group they were in.) Another 292 volunteers were given nicotine patches.
The volunteers in the trial used Elusion brand e-cigarettes because they are one of the most popular brands in New Zealand. Those who took 300 puffs with a nicotine cartridge inhaled 3 to 6 milligrams of nicotine, an amount equivalent to smoking one to five conventional cigarettes.
Six months after the volunteers passed their quit date, 7.3% of those using the e-cigarettes with nicotine had managed to refrain from smoking, along with 5.8% of those using patches and 4.1% of subjects who smoked e-cigarettes without nicotine. Those differences weren't big enough to be statistically significant, the study authors wrote.
Adverse events were slightly more common among those using electronic cigarettes than for those using patches, but the differences weren't statistically significant. None of the serious adverse events (including one death during the study) were related to any of the tested products.
There were several trends that pointed toward e-cigarettes with nicotine being superior to patches. Although most people in the study wound up relapsing, the ones who used the e-cigarettes held out longer (median time: 35 days) than the ones using patches (median time: 14 days).
At the six-month mark, those who used e-cigarettes with nicotine smoked 9.7 fewer conventional cigarettes per day, on average, while those who used patches had reduced their average daily cigarette use by 7.7. Put another way, 57% of volunteers who got e-cigarettes with nicotine had cut their regular cigarette use by at least half, while only 41% of volunteers who got patches could make the same claim.
In the trial, subjects used up a little more than one nicotine cartridge per day, on average. That would provide about 20% of the nicotine they would have inhaled through conventional smoking. Newer models of e-cigarettes that deliver more nicotine might result in higher quit rates by doing a better job of helping people overcome withdrawal, the researchers speculated.
Another complication was that 27% of the volunteers assigned to use patches dropped out of the study before it was over, compared with only 17% of volunteers assigned to use e-cigarettes with nicotine. Perhaps some volunteers signed up for the study in the hopes that they would get to use e-cigarettes and lost interest when they were given patches. If they had gotten e-cigarettes, they might have had better outcomes, the researchers wrote.
"Nicotine e-cigarettes were at least as effective as patches," the research team concluded.
Although the number of quitters in all groups was low and the study results were "tentative," they do offer "new and useful information" to smokers seeking to quit (and the health experts who want to help them), according to a commentary by Peter Hajek, director of the Tobacco Dependence Research Unit at Queen Mary, University of London.
Since e-cigarettes are "more attractive than patches to many smokers," they "have the potential to increase rates of smoking cessation," Hajek wrote. But that's not the best thing about them, he added:
"The main untapped potential of e-cigarettes, however, might not be in treatment of the minority of smokers seeking help with quitting, but rather as a safer consumer product for use by smokers in general," he wrote. "Such use could ultimately lead to the disappearance of combustible tobacco products and to the end of the epidemic of smoking-related disease and death."
Some public health experts, including Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, worry that e-cigarettes may have the opposite effect by getting children and teens hooked on nicotine. An e-cig habit could then grow into a traditional smoking habit.
Hajek said that was "theoretically possible" but not likely, based on the results of a handful of published studies. The best way to know for sure would be to watch and see whether sales of traditional cigarettes fall as e-cigarette use rises. "More data are needed," he wrote.
The e-cigarettes used in the trial were provided by their manufacturer, PGM International, but the company played no role in the study, according to the Lancet report. The study was funded by the Health Research Council of New Zealand.