Electronic cigarettes for smoking cessation.

Electronic cigarettes (e-cigarettes) are novel vaporising devices that, similar to nicotine replacement treatments, deliver nicotine but in lower amounts and less swiftly than tobacco smoking. However, they enjoy far greater popularity than these medications due in part to their behaviour replacement characteristics. Evidence for their efficacy as cessation aids, based on several randomised trials of now obsolete e-cigarettes, suggests a modest effect equivalent to nicotine patch. E-cigarettes are almost certainly far less harmful than tobacco smoking, but the health effects of long-term use are as yet unknown. Dual use is common and almost as harmful as usual smoking unless it leads to quitting. Population effects, such as re-normalising smoking behaviour, are a concern. Clinicians should be knowledgeable about these products. If patients who smoke are unwilling to quit or cannot succeed using evidence-based approaches, e-cigarettes may be an option to be considered after discussing the limitations of current knowledge.