Evaluation of Dependence and Nicotine Replacement Therapy-Supported Cessation Efforts Among Regular Electronic Cigarette Use

Nicotine replacement therapy (NRT) is a pharmacotherapy for smoking cessation approved bythe Federal Drug Administration (FDA). Most NRT products are available over the counter,making them easily accessible to not only cigarette smokers but also electronic cigarette(ECIG) users. Up to 40% of sampled ECIG users have endorsed use of a pharmacotherapy suchas NRT during an ECIG quit attempt ; however, the ability of NRT to promote ECIGcessation has been evaluated in only a two pilot studies. In these studies, 40.0‐42.9% ofECIG users reported ECIG abstinence after one or 6 months of NRT use. A major limitationof these studies is the reliance on self‐reports of ECIG abstinence.Unlike combustible tobacco products, ECIGs produce minimal carbon monoxide (CO).Consequently, exhaled CO tests used to confirm acute abstinence from products likecigarettes cannot be used for ECIG abstinence. Instead, researchers rely on measurementof nicotine or its metabolite cotinine, both of which can be detected in variousbiological fluids to confirm acute (e.g., hours) or longer‐term (e.g., days) abstinencefrom ECIGs. As has been highlighted by our previous work, however, the assays requiredfor these measures are not only costly and burdensome, they also are unable todistinguish use of ECIGs from other products like cigarettes or NRT. These challengeshave led to the development of assays for detecting propylene glycol (PG), a primaryingredient in ECIG liquid. Urine PG concentrations are significantly higher in regularECIG users relative to non‐tobacco users (25.6 vs 9.8 mcg/ml, respectively), as well asthat PG concentrations for ECIG users are reduced to non‐tobacco user levels (9.7 mcg/ml)following 12 hours of ECIG abstinence. These data show that PG can be measured in urine,and urine PG levels can be used to discriminate ECIG users from non‐users as well asverify short‐term ECIG abstinence.There is need for a greater understanding of ECIG dependence and evaluation of approachesto support ECIG cessation among non‐current smoking ECIG users. Data from the proposedproject will increase understanding of ECIG dependence, including indicators unique toECIG use relative to cigarette smoking that are not captured in extant ECIG dependencemeasures. This project also will provide data on how NRT may support ECIG cessation, aswell as an evaluation of approaches that can be used to verify ECIG use behaviors andabstinence beyond user self‐report. These latter data are urgently needed for thedevelopment of best practices for supporting ECIG cessation. Thus, successful completionof this project will ultimately support efforts to prevent negative health outcomesassociated with ECIG dependence and use.Aim 2 involves a between‐subjects study with two phases. Phase I involves a 3‐daybaseline period during which all participants will use their own ECIG ad lib. Phase IIinvolves randomization to one of two study conditions: NRT or abstinence. Those assignedto the NRT condition (n=50) will be provided with nicotine patches (21 mg) and lozenges(2 or 4mg) to use ad lib for up to 7 days (2 days of pre‐loading; 5 days ofintervention). Those assigned to the abstinence condition (n=50) will be asked to abstainfrom all nicotine/tobacco products for 5 days. Both phases will include regularassessment of quit motivation, subjective effects, product use, and toxicant exposure.Aim 3 involves using some of the outcomes from Aim 2 (i.e., objective and subjectivemeasures of ECIG use) to determine which methods offer the best measurement of ECIGuse/abstinence.