Summary
Introduction:
This text provides an in-depth analysis of the effects of flavors and nicotine on the subjective drug effects and ad libitum self-administration of e-cigarettes. The study also explores the impact of genetics on these effects, specifically focusing on individuals with higher and lower smoking-risk genotypes. The results of this study have important implications for the regulation of e-cigarettes and their impact on vulnerable subpopulations.
Key Points:
* The study uses a within-subjects design, with participants self-administering e-cigarettes containing different combinations of flavors (unflavored, menthol, fruit) and nicotine levels (0 mg/mL, 24 mg/mL) in directed and ad libitum conditions.
* Participants rated their subjective drug effects after each directed sub-block, and the number of puffs was recorded during ad libitum self-administration.
* Biochemical measures, including plasma cotinine, 3-hydroxycotinine, and nicotine metabolite ratio, were collected to characterize the sample and validate the paradigm.
* E-liquids were made-to-order and differed by flavor and nicotine concentration in a factorial design. Six separate programmable eVic Supreme e-cigarettes were used with built-in MyVapors software.
* Analyses were carried out using mixed effects models, with subjective drug effect summary score ratings and number of puffs as dependent variables.
* The study found that menthol partially ameliorated nicotine aversiveness, while fruit flavor increased the appeal of nicotine-free e-cigarettes.
* Individuals with the higher smoking-risk rs16969968 genotype reported greater craving alleviation following the directed administration of nicotine-containing e-liquids and self-administered more nicotine during ad libitum self-administration.
Main Message:
The study highlights the importance of considering the impact of flavors and genetics on e-cigarette use. The results suggest that menthol and fruit flavors increase e-cigarettes' appeal through distinct mechanisms, with menthol counteracting aversiveness and fruit flavor increasing appeal. Additionally, individuals with higher smoking-risk genotypes may be more susceptible to the reinforcing effects of nicotine in e-cigarettes. These findings have important implications for the regulation of e-cigarettes, particularly in terms of limiting flavor options and considering the potential impact on vulnerable subpopulations.
Citation
DeVito EE, Jensen KP, O’Malley SS, et al. Modulation of “Protective” Nicotine Perception and Use Profile by Flavorants: Preliminary Findings in E-cigarettes. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco. 2020;22(5):771-781. doi:10.1093/ntr/ntz057
