Free-Base Nicotine or Nicotine Salt e-Liquids in Current E-Cigarette Smokers, PeloPET Study

This clinical trial studies the effect of free-base compared with nicotine salt based e-liquids on electronic cigarette (EC) puffing behavior, abuse liability, and deposition and absorption of nicotine in the respiratory tract and rate of uptake in the brain in current EC smokers. The results from this study may provide much needed scientific information to public health officials and regulators.

PRIMARY OBJECTIVES:

I. To examine the influence of nicotine form on puffing behavior and abuse liability.

II. To evaluate the influence of nicotine form and concentration on nicotine distribution in the brain and respiratory tract.

OUTLINE:

VISIT 1: Patients sample 4-liquids to determine whether they can vape the unflavored e-liquid without coughing

Patients are randomized to 1 of 2 arms.

ARM I:

VISIT 2: Patients receive 1 puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 minutes (min) head and 5 min chest positron emission tomography (PET)/computed tomography (CT) and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest PET/CT.

VISIT 3: Patients receive 1 puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest

ARM II:

VISIT 2: Patients receive 1 puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest.

VISIT 3: Patients receive 1 puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest PET/CT.

Eligibility Criteria:
Inclusion Criteria:

* A current exclusive e-cigarette user (\>= 1 vaping bout per day) for at least the past 6 months (confirmed by NicAlert saliva testing strip)
* Between 21-50 years old
* Willing to provide informed consent and abstain from all tobacco and nicotine use for at least 12 hours prior to visits 2 and 3
* Willing to participate in 3 laboratory visits
* Read and speak English
* If utilizing study provided rideshare services, will need to live within 20 miles of Wake Forest University

Exclusion Criteria:

* Self-reported diagnosis of lung disease including asthma, cystic fibrosis, or chronic obstructive pulmonary disease
* Unstable or significant psychiatric conditions (past and stable conditions will be allowed)
* History of cardiac event or distress within the past 3 months
* Currently pregnant (as indicated by urine pregnancy test at the start of each laboratory visit), planning to become pregnant, or breastfeeding (women only)
* Use of other tobacco products (e.g., cigarette, cigar, etc.) \> 5 days in the past month
* Currently engaging in a tobacco product cessation attempt