Abuse liability assessment of an electronic cigarette in combustible cigarette smokers

Abstract

Under certain conditions, electronic cigarettes (e-cigs) can deliver nicotine to and suppress tobacco abstinence symptoms in cigarette smokers. Growing popularity of e-cigs raises abuse liability concerns. This study's purpose was to compare the abuse liability of an e-cig (1.5 Ohm, 3.3 V) filled with 36 mg/mL or 0 mg/mL nicotine to an Food and Drug Administration (FDA)-approved nicotine inhaler (IN) and participants' own brand (OB) of cigarettes. Smokers (N = 24) completed four sessions in which they completed the multiple-choice procedure, and plasma nicotine concentration and subjective effects were measured. Mean (SD) multiple-choice procedure crossover point was $0.87 (1.0) for the 36-mg/mL nicotine e-cig and $0.96 (1.2) for the 0-mg/mL e-cig, significantly higher than the IN mean of $0.32 (0.6) but significantly lower than the OB cigarette mean of $1.42 (1.4). Ten puffs from an own-brand cigarette increased mean plasma nicotine concentration from 3.55 (2.8) to 13.64 (9.8) ng/mL, as compared to an increase from 3.16 (1.8) to 8.51 (5.4) ng/mL for the 36-mg/mL e-cig. The 36-mg/mL e-cig reduced nicotine abstinence symptoms more than the 0-mg/mL e-cig, and both e-cigs were rated as more reinforcing than the inhaler but less reinforcing than participants' OB cigarettes (ps < .05). Results suggest that the e-cig examined had higher abuse liability than the IN but lower than combustible cigarettes. These data and methods may be useful for policymakers by revealing how e-cig abuse liability compares to tobacco/nicotine products with abuse liability profiles that are well established. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Figure 1.

Mean (+SEM) MCP crossover point (Panel A; n = 24), VAS score for the item “Did the product taste good?” (Panel B; n = 22), and VAS score for the item “Was the product satisfying?” (Panel C; n = 22) for ECIG-naive cigarette smokers after use of products. Asterisks (*) indicate significant difference from OB and plus sign (+) indicates a significant difference from IN (t-test, ps <.05).

Figure 2.

Mean (±SEM) plasma nicotine concentration (Panel A; n = 24), VAS score for the item assessing “Craving a cigarette/nicotine” (Panel B; n = 24), and Factor 1 score (Panel C; n = 21) for ECIG-naive cigarette smokers. Arrows represent the onset of each 10-puff product bouts (30-seconds between each puff). Filled symbols indicate a significant difference from baseline. Asterisks (*) indicates a significant difference from OB, plus sign (+) indicates significant difference from IN, and (#) pound symbol indicates significant difference from ECIG_36 at that time-point for that product (t-test).