Electronic nicotine delivery devices (ENDD), commonly referred to as e-cigarettes, are vaporized nicotine delivery systems.1 While some products are nicotine-free, most devices consist of a battery-operated heater, flavorings and a nicotine cartridge.1,2 Great variability exists among these products in terms of nicotine concentration. Most cartridges contain 6-24 mg of nicotine, however some concentrations have been documented as high as 100 mg.3 Currently unregulated by the FDA, e-cigarette cartridges contain nicotine and other items such as propylene glycol, a known irritant when inhaled, and other potentially harmful chemical constituents including genotoxins and animal carcinogens.2-4 While the safety of these cartridges has yet to be determined, many consumers perceive e-cigarettes to be less harmful than the traditional cigarette because vapor, rather than smoke, is inhaled.3 The perception of e-cigarettes as being the safer cigarette has led many patients to use them as a smoking cessation aid. There are currently no scientifically determined instructions for use of e-cigarettes as a smoking cessation aid due to variable nicotine cartridge concentrations and unknown dosage delivery upon inhalation.3 While e-cigarettes efficacy in quitting remains controversial, a few studies have been published recently comparing the efficacy of these devices to established nicotine replacement therapies.1
Two studies published by Bullen and colleagues found electronic cigarettes to be effective smoking cessation aids.1,5 The first study, published in 2010, randomized 40 adults that smoked greater than or equal to ten cigarettes daily into the following three groups: e-cigarette with nicotine (Ruyan V8, 16mg), e-cigarette without nicotine, and Nicorette nicotine inhalator. This single blind, randomized, cross-over trial identified the nicotine e-cigarette to produce less irritation of the mouth and throat (p<0.002) compared to the Nicorette inhalator. The 16 mg nicotine e-cigarette lessened participants’ desire to smoke compared to placebo (p=0.006), but did not show a statistically significant difference in desire to smoke compared to the Nicorette inhalator.5
The authors’ second study was recently published in Lancet in 2013. It was a three parallel group, randomized, superiority trial comparing e-cigarettes to the nicotine patch and placebo. The study’s primary outcome was continuous smoking abstinence, defined as five or less cigarettes total in the six months post quit day. A total of 657 participants were randomized in a 4:4:1 ratio to e-cigarettes (16mg/cartridge), patch (21mg) or placebo e-cigarettes plus voluntary low-level behavioral support. Results of the study showed abstinence at six months post quit date to be highest with e-cigarettes (7.3%), followed by the patch (5.8%) and placebo e-cigarettes (4.1%.) However, the number of participants reaching the abstinent goal did not achieve power, so the statistical significance of the primary endpoint could not be determined. The adherence to the study treatment was significantly higher in the e-cigarette group as compared to the nicotine patch group (p<0.001.) The study concluded that e-cigarettes may be as effective as the patch at achieving cessation at six months, but further research reaching an appropriate power is necessary to validate that claim.1
Overall, not enough data exists to support the use of e-cigarettes as a smoking cessation aid. Initial studies show it may be as effective as the nicotine patch, however safety has yet to be fully examined. In addition, there is a lack of standardization and purity among available products and the World Health Organization strongly advises against the use of electronic ...