This is a single-site, randomized, crossover study of experienced adult e-cigarette users to assess nicotine exposure, toxicant exposure, and the short-term CV effects of e-liquid pH. Three e-liquid pH conditions will be assessed on all participants: 5, 7, and 9.~Hypothesis 2a: The rate of systemic nicotine absorption is inversely related to e-liquid pH and results in lower peak blood nicotine levels at higher pH.~Hypothesis 2b: Heart rate acceleration will decrease and subjective measures of sensation in the throat, reward, and satisfaction will increase with increasing e-liquid pH.
This study will examine the short-term cardiovascular (CV) effects of e-liquid pH in a randomized, crossover clinical and behavioral pharmacology study of experienced adult e-cigarette users (N=21). The specific aim of the study is to assess the impact of changes in e-liquid pH on nicotine pharmacokinetics, cardiovascular, and subjective effects of e-cigarettes.