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

Aim To describe systemic nicotine exposure and subjective effects of electronic cigarettes (e‐cigarettes) in people who use both e‐cigarettes and cigarettes (dual users), including within‐subject comparisons of e‐cigarette and cigarette use. Design Two‐arm, counterbalanced cross‐over study. Participants used their usual brand of e‐cigarette or cigarette during a standardized session in a 2‐week study. Setting Hospital research ward, San Francisco, CA, USA. Participants Thirty‐six healthy (eight women, 28 men) participants. Measurements Plasma nicotine was analyzed by gas chromatography–tandem mass spectrometry; nicotine withdrawal, urge to smoke and vape, affective states, craving, satisfaction and psychological reward were measured by standardized questionnaires. Findings Compared with cigarettes, average maximum plasma nicotine concentration (Cmax) was lower with e‐cigarettes [6.1 ± 5.5 ng/ml, mean ± standard deviation (SD) versus 20.2 ± 11.1 ng/ml, P