Twenty‐four‐hour subjective and pharmacological effects of ad‐libitum electronic and combustible cigarette use among dual users

Abstract

Background and Aims Relative pharmacological effects of e-cigarettes and cigarettes during 24 hours of ad-libitum use have not been described. In this study, 24-hour blood plasma nicotine concentrations and 48-hour subjective effects with use of cigarettes and e-cigarettes were measured among dual users. Design Two-arm within-subject cross-over design with preferred e-cigarette or cigarette ad-libitum use over 48 hours. Setting Hospital research ward in San Francisco, California, USA. Participants Thirty-six healthy dual users of e-cigarettes and cigarettes (n = 8, 25% females). Measurements Twenty-four-hour blood plasma nicotine and cotinine concentrations and 48-hour self-reported nicotine withdrawal symptoms and rewarding effects. Findings Analyses used analysis of variance (ANOVA)-based mixed models with order of product (e-cigarette or cigarette) and product type (combustible cigarette or type of e-cigarette) as fixed effects, and subject as a repeated effect. During a 24-hour period, e-cigarettes produced lower nicotine exposure than cigarettes for the majority of users, although 25% received more nicotine from e-cigarettes, which was predicted by more frequent e-cigarette use or greater dependence. Compared to cigarette smoking, nicotine exposure for variable-power tank users was similar, while cig-a-like (t (30) = 2.71, P = 0.011, d = 0.745) and fixed-power tank users (t (30) = 3.37, P = 0.002, d = 0.993) were exposed to less nicotine. Cigarettes were rated higher than e-cigarettes on some desirable subjective effects (e.g. psychological reward, t (322) = 7.24 P < 0.001, d = 0.432), but withdrawal symptom reduction was comparable. No differences were found between e-cigarette types, but Bayes factors indicate that these measures were insensitive.Conclusions During a 24-hour period in a hospital setting in the United States, nicotine exposure for dual users of ecigarettes and cigarettes was similar when using cigarettes or variable-power tank devices only but was lower for those using cig-a-like or fixed-power devices only. Despite lower nicotine levels, all types of e-cigarette were effective in preventing withdrawal symptoms. E-cigarettes were rated less rewarding than cigarettes.

Differences in nicotine intake and effects from electronic and combustible cigarettes among dual users

“…clusters of greater than 10 puffs which are then followed by smaller clusters of puffs [36,37], suggesting that the fixed puffing protocol of 10-15 puffs has real-world relevance. In addition, consistent with our findings from the fixed puffing protocol, we report in a separate paper that participants showed lower nicotine intake and reported lower psychological reward but similar withdrawal suppression with e-cigarettes compared to cigarettes during a day of ad libitum access [7]. These findings further support the idea that differences between e-cigarettes and cigarettes in nicotine intake and subjective effects from a fixed puffing protocol may be indicative of differences in nicotine intake and subjective effects from a longer period of ad libitum access.…”

Comparison of Systemic Exposure to Toxic and/or Carcinogenic Volatile Organic Compounds (VOC) during Vaping, Smoking, and Abstention

“…(Plasma nicotine AUC is reported in another article; ref. 27). Finally, we computed the frequencies of participants with e-cigarette to abstention biomarker level ratios of at least 1.25 or at least 1.50 by device type and flavor category, representing at least 25% and 50% higher biomarker levels from e-cigarette use compared with abstention respectively.…”

Clinical Pharmacology of Electronic Nicotine Delivery Systems (ENDS): Implications for Benefits and Risks in the Promotion of the Combusted Tobacco Endgame

“…A second approach is to sample blood nicotine for periods throughout the day with ad libitum use, which provides a more realistic estimate of nicotine intake. This has been done with brief (90‐minute) or longer (24‐hour) sessions 44,45 . Another way to assess daily intake of nicotine is to measure cotinine in blood, saliva, or urine or the sum of nicotine and its metabolites in urine at steady state 21,46,47 …”

“…In 1 study of 36 dual users using only e‐cigarettes or cigarettes ad libitum, plasma nicotine AUC was on average 30% lower while vaping, but 25% of individuals took in as much or more from vaping compared with smoking (Figure 3). 45 Circadian plasma nicotine level differed by type of device (Figure 4). Of interest, the circadian pattern of nicotine intake differed from participant to participant, but was similar while vaping versus smoking, as seen in data from 3 of the same pod‐type device users (Figure 5).…”