Vaping High vs. Low Nicotine E-Liquid
- Conditions
- Cardiovascular Risk FactorNicotine Dependence
- Registration Number
- NCT04047836
- Lead Sponsor
- University of California, San Francisco
- Brief Summary
This study will examine the effects of electronic cigarette e-liquid nicotine content in a randomized, crossover clinical and behavioral pharmacology study of experienced adult e-cigarette users (N=36). The specific aim is to determine the impact of nicotine content of e-liquid on nicotine pharmacology, systemic exposure to toxic volatile organic compounds, and short-term cardiovascular effects.
- Detailed Description
This is a within-subjects, crossover design of advanced electronic cigarette users in which we will examine nicotine pharmacokinetics, subjective effects, daily nicotine intake and nicotine titration, short-term cardiovascular effects, and toxicant exposure when participants are using low vs. high nicotine e-liquids.
Hypothesis 1: E-cigarette users will titrate their intake of nicotine such that they will inhale fewer aerosol toxicants and suffer less harm to health when using higher vs. lower nicotine content e-liquids.
Hypothesis 2: Compared to low nicotine, high nicotine e-liquid use will have similar cardiovascular effects throughout the day (due to compensatory behavioral changes), with similar effects on heart rate, blood pressure, and catecholamine release.
Hypothesis 3: Exposure to volatile organic compounds (VOCs) will be lower when vaping high nicotine e-liquids compared to low nicotine e-liquids.
Recruitment & Eligibility
- Status
- WITHDRAWN
- Sex
- All
- Target Recruitment
- Not specified
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Healthy on the basis of medical history and limited physical examination, as described below:
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Heart rate < 105 beats per minute (BPM)*
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Systolic Blood Pressure < 160 and > 90*
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Diastolic Blood Pressure < 100 and > 50*
*Considered out of range if both machine and manual readings are above/below these thresholds.
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Age: >= 21 years
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Age: <= 70 years
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Current regular user of open tank electronic cigarette (EC) (at least 20 times in the past 30 days) with e-liquid nicotine of 3-6 mg/mL.
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Non-smoker or non-daily cigarette smokers agreeing to abstain from cigarettes for the duration of the study.
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Saliva cotinine >50 ng/mL and/or NicAlert=6
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Carbon monoxide >= 5 ppm or per discretion of Principal Investigator
- Medical
- Heart disease
- Seizures
- Cancer
- Thyroid disease (okay if controlled with medication)
- Diabetes
- Hepatitis B or C or Liver disease
- Glaucoma
- Kidney disease or urinary retention
- History of stroke
- An ulcer in the past year
- Active use of an inhaler for Asthma or Chronic obstructive pulmonary disease (COPD)
- Psychiatric conditions
- Current or past schizophrenia, and/or current or past bipolar disorder
- Major depression, current or within the past year
- Major personality disorder
- Participants with current or past minor or moderate depression and/or anxiety disorders will be reviewed by the PI and considered for inclusion
- History of psychiatric hospitalizations is not exclusionary, but study participation will be determined as per PI's approval
- Drug/Alcohol Dependence
- Alcohol or illicit drug dependence within the past 12 months with the exception of those who have recently completed an alcohol/drug treatment program
- Positive toxicology test for illicit drugs at the screening visit (THC & prescribed medications okay)
- Opioid replacement therapy (including methadone, buprenorphine, or other)
- Psychiatric medications
- Current regular use of any psychiatric medications with the exception of Selective Serotonin Reuptake Inhibitors (SSRIs) and serotonin-norepinephrine reuptake Inhibitors (SNRIs) and current evaluation by the PI that the participant is otherwise healthy, stable, and able to participate.
- Medications
- Use of medications that are inducers of nicotine metabolizing enzyme CYP2A6 (Example: rifampicin, carbamazepine, phenobarbital, and other anticonvulsant drugs).
- Use of sympatholytic medications for cardiovascular conditions including hypertension (Example: beta and alpha-blockers)
- Concurrent use of nicotine-containing medications
- Any stimulant medications (example: Adderall) generally given for attention deficit hyperactivity disorder (ADHD) treatment
- Other/Misc. Chronic Health Conditions
- Oral thrush
- Fainting (within the last 30 days)
- Other "life threatening illnesses" as per PI's discretion
- Pregnancy
- Pregnancy (self-reported and urine pregnancy test)
- Breastfeeding (determined by self-report)
- Concurrent participation in another clinical trial
- Inability to read and write in English
- Planning to quit vaping within the next 60 days
- Concurrent regular use of marijuana (occasional users of these products may be enrolled if they agree to abstain from their use during the period of the study)
- Use of other tobacco products, smokeless tobacco, pipes, cigars/cigarillos, blunts/spliffs (no more than 10 times in the past month and must agree to abstain from their use during the period of the study)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Primary Outcome Measures
Name Time Method Nicotine Exposure Day 1 of each Arm Plasma nicotine area under curve (AUC) (ng/ml\*h)
Cardiovascular Effects: Heart Rate Days 1-3 of each Arm Participant heart rate will be measured in beats per minute throughout the inpatient stay.
Cardiovascular Effects: Systolic Blood Pressure Day 2 of each Arm Participant systolic blood pressure will be taken for 24 hours during ad-lib e-cigarette use.
Cardiovascular Effects: Diastolic Blood Pressure Day 2 of each Arm Participant diastolic blood pressure will be taken for 24 hours during ad-lib e-cigarette use.
- Secondary Outcome Measures
Name Time Method Vaping Topography: Puff Duration Days 1-3 of each Arm Vaping topography measures will be obtained from self-reported participant vaping log during the ad libitum sessions and measured as seconds per puff.
Vaping Topography: Puff Number Days 1-3 of each Arm Vaping topography measures will be obtained from self-reported participant vaping log during the ad libitum sessions and measured as puffs per minute.
Vaping Topography: Inter-Puff Interval Days 1-3 of each Arm Vaping topography measures will be obtained from self-reported participant vaping log during the ad libitum sessions and measured as seconds/minutes between puffs.
Trial Locations
- Locations (2)
University of California, San Francisco
🇺🇸San Francisco, California, United States
Zuckerberg San Francisco General Hospital
🇺🇸San Francisco, California, United States
University of California, San Francisco🇺🇸San Francisco, California, United States