Nicotine delivery and users' reactions to Juul compared with cigarettes and other e-cigarette products.

AIMS: To assess the pharmacokinetic (PK) profile of, and users' reactions to, Juul (59 mg nicotine/ml) as an indication of its therapeutic and dependence potential. DESIGN: Cross-over, within-subjects study in which participants attended after overnight abstinence on separate sessions and smoked a cigarette or used Juul or eight other types of e-cigarettes (EC) ad libitum for 5 minutes. The Juul product used was the version available in the United States that has more nicotine in the e-liquid than the one available in the European Union. SETTING: Laboratory setting in the United Kingdom. PARTICIPANTS: Twenty dual users (smokers who also vape) provided data on Juul and cigarettes, with eight also providing data on other EC products. MEASUREMENTS: At each session, number of puffs taken was counted during the 5-minute product use period and blood samples were taken at baseline and at 2, 4, 6, 8, 10 and 30 minutes after starting smoking/vaping and analysed for nicotine. Participants also monitored their urges to smoke and rated the products on a range of characteristics. FINDINGS: Juul's PK profile was close to the PK profile of cigarettes [maximum concentration (Cmax ) = 20.4 versus 19.2 ng/ml; time to maximum concentration (Tmax ) = 4 versus 6 minutes; area under the curve (AUC): 307.9 versus 312.6, respectively]. Compared with other EC products, Juul had shorter Tmax [4 minutes, (IQR = 2.5-4.0) versus 6.3 minutes, (IQR = 4.7 - 8.1), P = 0.012] and higher Cmax (28.9 (SD = 15.6) versus 10.6 (SD = 5.5), P = 0.013) despite a lower number of puffs (12.5 (SD = 4.2) versus 17.0 (SD = 4.2), P = 0.084). Compared with other e-cigarette products, it also provided faster reduction of urges to smoke and obtained more favourable subjective ratings. CONCLUSION: Juul's PK profile and user ratings suggest that it could be more effective than other EC products in helping smokers to quit smoking, but it may also have a higher potential to generate regular use in non-smokers.

Are 'dual users' who smoke and use e-cigarettes interested in using varenicline to stop smoking altogether, and can they benefit from it? A cohort study of UK vapers.

OBJECTIVES: Smokers who use e-cigarettes (EC) do so mostly to stop smoking, but many continue to use both products. It is not known whether these 'dual users' are interested in stop-smoking medications and whether they can benefit from them. SETTING, PARTICIPANTS AND MEASURES: Dual users were recruited over social media and posted study questionnaire and saliva kits at baseline, 3 and 6 months. Those interested in varenicline were posted the medication and received weekly calls over the first 6 weeks, followed by three calls at fortnightly intervals. RESULTS: Of 204 participants, 124 (61%, CI=54% to 68%) expressed interest in receiving varenicline and 80 (39%, CI=32% to 45%) started varenicline (varenicline users, VU). VU were more dependent smokers (F=6.2, p=0.01) with higher cigarette consumption (F=8.7, p<0.01) who were using stronger nicotine e-liquids (F=13.9, p<0.001) than dual users not opting for varenicline (varenicline non-users, VN). In terms of abstinence for at least 3 months at the 6-month follow-up, VU were more likely than VN to report abstinence from smoking (17.5% vs 4.8%, p=0.006, RR=3.6, CI:1.4 to 9.0), vaping (12.5% vs 1.6%, p=0.007, RR=7.8, CI:1.7 to 34.5) and both smoking and vaping (8.8% vs 0.8%, p=0.02, RR=10.9, CI:1.4 to 86.6). The differences were significant across sensitivity analyses (RRs=4.9 to 14.0; p=0.02 to p<0.001 at 3 months; RRs=3.0 to 14.0; p=0.01 to p<0.001 at 6 months). VU reported a greater reduction in enjoyment of vaping by the end of the varenicline use period (F=4.1, p=0.04) and recorded a significantly greater reduction in nicotine intake than VN at 3 months (F=13.9, p<0.001) and 6 months (F=26.5, p<0.001). CONCLUSION: Varenicline offered to dual users is likely to promote successful abstinence from both smoking and vaping, although a randomised trial is needed to confirm this. Among dual users who want to stop smoking, there seems to be a high level of interest in smoking-cessation treatments.