[Electronic cigarette--a safe substitute for tobacco cigarette or a new threat?].

The aim of this paper was to summarize up-to-date data on the new emerging nicotine containing product 'electronic cigarette', commonly referred as e-cigarette. We presented data on prevalence and popularity of various brands and models on domestic markets. Development of the new products with technical and chemical modifications was also described. We reviewed studies on chemical composition and efficacy of nicotine delivery from e-cigarettes and discussed its potential use as nicotine replacement for tobacco cigarettes. Regulatory policies on e-cigarette sale as nicotine containing product were also discussed. We concluded that e-cigarette might be an effective harm reduction tool but little is known about its safety, especially when used for a long time. Despite many positive findings from surveys among e-cigarettes users, there is need for comprehensive state-of-the-at clinical trials to show efficacy of e-cigarette as smoking cessation tool.