Electronic nicotine delivery systems ("e-cigarettes"): review of safety and smoking cessation efficacy

Abstract

Background and objectives: Cigarette smoking is common among cancer patients and is associated with negative outcomes. Electronic nicotine delivery systems ("e-cigarettes") are rapidly growing in popularity and use, but there is limited information on their safety or effectiveness in helping individuals quit smoking.

Data sources: The authors searched PubMed, Web of Science, and additional sources for published empirical data on safety and use of electronic cigarettes as an aid to quit smoking.

Review methods: We conducted a structured search of the current literature up to and including November 2013.

Results: E-cigarettes currently vary widely in their contents and are sometimes inconsistent with labeling. Compared to tobacco cigarettes, available evidence suggests that e-cigarettes are often substantially lower in toxic content, cytotoxicity, associated adverse effects, and secondhand toxicity exposure. Data on the use of e-cigarettes for quitting smoking are suggestive but ultimately inconclusive.

Conclusions: Clinicians are advised to be aware that the use of e-cigarettes, especially among cigarette smokers, is growing rapidly. These devices are unregulated, of unknown safety, and of uncertain benefit in quitting smoking.

Implications for practice: In the absence of further data or regulation, oncologists are advised to discuss the known and unknown safety and efficacy information on e-cigarettes with interested patients and to encourage patients to first try FDA-approved pharmacotherapies for smoking cessation.

Keywords: carcinogens; e-cigarettes; electronic nicotine delivery systems; nicotine; personal vaporizers; smoking; toxicity; vapers; vaping.

Figure 1

Typical components of an electronic cigarette. Source: Reprinted from Foulds et al. 2011 with permission from John Wiley and Sons, © 2011 Blackwell Publishing Ltd.

Figure 2

Flow diagram of literature search, screening, and selection.