A wide range of electronic cigarette (EC) devices, from small cigarette-like (first-generation) to new-generation high-capacity batteries with electronic circuits that provide high energy to a refillable atomizer, are available for smokers to substitute smoking. Nicotine delivery to the bloodstream is important in determining the addictiveness of ECs, but also their efficacy as smoking substitutes. In this study, plasma nicotine levels were measured in experienced users using a first- vs. new-generation EC device for 1 hour with an 18 mg/ml nicotine-containing liquid. Plasma nicotine levels were higher by 35–72% when using the new- compared to the first-generation device. Compared to smoking one tobacco cigarette, the EC devices and liquid used in this study delivered one-third to one-fourth the amount of nicotine after 5 minutes of use. New-generation EC devices were more efficient in nicotine delivery, but still delivered nicotine much slower compared to tobacco cigarettes. The use of 18 mg/ml nicotine-concentration liquid probably compromises ECs’ effectiveness as smoking substitutes; this study supports the need for higher levels of nicotine-containing liquids (approximately 50 mg/ml) in order to deliver nicotine more effectively and approach the nicotine-delivery profile of tobacco cigarettes.
Published: 26 February 2014
Link to publication:
- Konstantinos E. Farsalinos,
- Alketa Spyrou,
- Kalliroi Tsimopoulou,
- Christos Stefopoulos,
- Giorgio Romagna
- Vassilis Voudris
Electronic cigarettes (ECs) have been introduced to the market in recent years as alternatives to smoking. They are considered part of tobacco harm reduction, a strategy of reducing adverse health effects by providing low-risk nicotine products to substitute smoking1. They deal with both the psycho-behavioral (through motor simulation and sensory stimulation) and the chemical (through delivery of nicotine) aspects of smoking addiction2. ECs mainly consist of a lithium battery and a part called atomizer, where the liquid is stored and evaporated by applying electrical current to a resistance and wick setup. There is a substantial variability of devices; small devices, looking similar to tobacco cigarettes (commonly referred as first-generation), consist of a low-capacity batteries and polyfil-filled atomizers, while new-generation devices consist of larger-capacity batteries, larger atomizers and electronic circuits providing the ability to set the power delivery to the atomizer.
The growing popularity of ECs3, 4 has raised significant controversy in public health authorities. Organizations such as the World Health Organization and Food and Drug Administration have expressed concerns about the safety of e-cigarettes and the effects of nicotine intake. Recently, European Union has developed a new regulation which implements an upper limit of 20 mg/ml nicotine concentration in liquids that are used with ECs5. The decision was based on a study from our group, in which nicotine consumption and delivery to the user was evaluated6, 7. However, the route, speed and amount of nicotine absorption (and subsequent nicotine levels in plasma) are important determinants of the efficacy of ECs to serve as smoking substitutes and of any concerns about nicotine overdose or intoxication. Data on nicotine absorption are scarce. Initially, EC use (commonly called vaping) was found to deliver minimal amounts of nicotine to the user as measured by plasma nicotine levels8, 9. However, there has been a fast evolution of new, more efficient devices, and devices used at the time of those experiments are currently outdated and off the market. Surveys have shown that new-generation devices are more popular in dedicated EC users and a significant proportion of these users report complete smoking cessation10, 11. However, no study has evaluated nicotine absorption from such devices. Therefore, the purpose of this study was to compare the nicotine absorption from a first- vs. a new-generation device in experienced vapers.
The use of 18 mg/ml nicotine-concentration liquid probably compromises ECs’ effectiveness as smoking substitutes; this study supports the need for higher levels of nicotine-containing liquids (approximately 50 mg/ml) in order to deliver nicotine more effectively and approach the nicotine-delivery profile of tobacco cigarettes.