Vaping THC From Electronic Cigarettes (V-PAX)
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| ClinicalTrials.gov Identifier: NCT02955329 |
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Recruitment Status :
Completed
First Posted : November 4, 2016
Last Update Posted : November 10, 2020
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| Condition or disease | Intervention/treatment | Phase |
|---|---|---|
| Marijuana Dependence | Drug: Nicotine only Drug: THC only Drug: Nicotine and THC Device: PAX Loose Leaf Vaporizer | Phase 3 |
Electronic cigarettes (e-cigarettes) have proliferated at a rapid rate since their introduction into the US market in 2007, and their use as a form of nicotine delivery far outpaced the science base (1, 2). Although the design of these devices continues to evolve, we have previously described nicotine intake, systemic retention, pharmacokinetics, and vaping behavior associated with self-administration of e-cigarettes (3, 4) . We demonstrated that while the shape of the plasma nicotine concentration-time curve for e-cigarettes is similar to tobacco cigarettes, the maximum plasma nicotine concentration is, on average, lower for e-cigarettes. During ad libitum access, e-cigarettes were vaped intermittently in groups of 2-5 puffs or single puffs such that plasma nicotine levels rose gradually and peaked at the end of the 90-minute session. This differs from the rapid increase in plasma nicotine observed during controlled use of e-cigarettes or during tobacco cigarette smoking. Taken together, these results indicate that e-cigarettes have the potential to produce and sustain nicotine addiction but their use and abuse liability may differ from tobacco cigarettes.
The study is designed as a within-subjects, single-blinded crossover study. Fourteen smokers of tobacco cigarettes and cannabis will switch between three conditions, namely: (a) vaping cannabis leaf, (b) vaping tobacco containing nicotine and (c) vaping a combination of cannabis leaf and tobacco containing nicotine. All participants will vape each product with the PAX loose-leaf vaporizer, which will be purchased by the study team. The cannabis leaf will be obtained through the National Institute on Drug Abuse Drug Supply Program. The tobacco-containing nicotine, used in conditions (b) and (c) will come from commercially available Marlboro brand cigarettes. The same amount of cannabis or tobacco will be used in all conditions.
The study will be conducted during three outpatient visits separated by at least 48 hours. The order of treatment (cannabis leaf, tobacco with nicotine, cannabis leaf & tobacco with nicotine) will be counterbalanced between subjects. Subjects will be blinded to the content of the vaporizer on the study day but will be told during screening that they will vape cannabis alone, tobacco alone, and cannabis plus tobacco with nicotine.
While scientists struggle to keep up with the latest electronic cigarette trends, the use of these devices for cannabis rather than nicotine is increasingly prevalent. electronic cigarette use is not restricted to nicotine. Marijuana, the most widely used illicit drug (5) has traditionally been combusted but the vaping of loose-leaf marijuana and THC oil has been increasing (6). the latest national data show that 7.6% of current marijuana users (past 30 days) and 9.9% of ever cannabis users (lifetime) administered THC through a vaporizer or electronic device (6) (the study did not differentiate between vaporizers and electronic devices like e-cigarettes). The prevalence of vaped marijuana or THC is higher among younger adults. Prevalence of vaped marijuana/THC among 18-24 and 25-34 year-old ever marijuana users was 19.3% and 16.3%, respectively, compared to 8.8% for 35-49 year-olds and 5.7% for those 50 years and over (6). A recent study also showed high rates of cannabis vaping among high school students (18.0% among ever e-cigarette users) (7). Smoking of a combination of tobacco and marijuana in cigarette form is also common, particularly in Europe (8) (9). However, very little is known about the safety and pharmacokinetics of this co-administration making it a critical area of research.
| Study Type : | Interventional (Clinical Trial) |
| Actual Enrollment : | 8 participants |
| Allocation: | Randomized |
| Intervention Model: | Crossover Assignment |
| Masking: | Single (Participant) |
| Primary Purpose: | Other |
| Official Title: | Vaping THC From Electronic Cigarettes: a Novel Evaluation of Intake and Pharmacokinetics |
| Actual Study Start Date : | March 20, 2019 |
| Actual Primary Completion Date : | November 30, 2019 |
| Actual Study Completion Date : | November 30, 2019 |
| Arm | Intervention/treatment |
|---|---|
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Experimental: Nicotine
Participants will vape tobacco leaves with nicotine out of the PAX device.
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Drug: Nicotine only
In the Nicotine only arm, participants will vape tobacco leaves with nicotine out of the PAX device. Device: PAX Loose Leaf Vaporizer In all three arms, the participant will be using the same PAX electronic cigarette device. The only difference is whether the participant will be vaping nicotine only, THC only, or nicotine and THC. |
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Experimental: THC
Participants will vape marijuana leaves with THC (Tetrahydrocannabinol) out of the PAX device.
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Drug: THC only
In the THC only arm, participants will vape marijuana leaves with nicotine out of the PAX device. Device: PAX Loose Leaf Vaporizer In all three arms, the participant will be using the same PAX electronic cigarette device. The only difference is whether the participant will be vaping nicotine only, THC only, or nicotine and THC. |
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Experimental: Nicotine/THC
Participants will vape flavorless 6% nicotine e-liquid, followed by THC (Tetrahydrocannabinol) out of the PAX device.
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Drug: Nicotine and THC
In the nicotine/THC arm, participants will vape marijuana leaves with THC combined with tobacco leaves with nicotine out of the PAX device. Device: PAX Loose Leaf Vaporizer In all three arms, the participant will be using the same PAX electronic cigarette device. The only difference is whether the participant will be vaping nicotine only, THC only, or nicotine and THC. |
- Delivered and Retained Doses [ Time Frame: Study Day 1-3 ]Delivered THC and nicotine doses are estimated as the change in e-cigarette weight × concentration of THC or nicotine in e-liquid. The amount of THC or nicotine systemically retained is estimated as delivered dose minus amount in gas traps.
- Peak THC concentration (Cmax) [ Time Frame: Study Day 1-3 ]Compare mean peak concentration of THC between vaped loose-leaf cannabis vs. mixture of cannabis and tobacco containing nicotine.
- Peak nicotine concentration (Cmax) [ Time Frame: Study Day 1-3 ]Compare mean peak concentration of nicotine between vaped loose-leaf tobacco containing nicotine vs. mixture of cannabis and tobacco containing nicotine.
- THC exposure [ Time Frame: Study Day 1-3 ]Compare mean exposure of nicotine using AUC (area under the blood/plasma concentration-time curve) between vaped loose-leaf cannabis vs. mixture of cannabis and tobacco containing nicotine.
- Nicotine exposure [ Time Frame: Study Day 1-3 ]Compare mean exposure of nicotine using AUC (area under the blood/plasma concentration-time curve) between vaped loose-leaf tobacco containing nicotine vs. mixture of cannabis and tobacco containing nicotine.
- Heart rate [ Time Frame: Study Day 1-3 ]Heart rate monitoring by pulse oximeter
- Liking [ Time Frame: Study Day 1-3 ]Drug Effect Questionnaire (DEQ-5)
- Craving [ Time Frame: Study Day 1-3 ]Marijuana Craving Questionnaire-Short Form (MCQ-SF)
- Reward [ Time Frame: Study Day 1-3 ]Minnesota Behavioral Scale or (Minnesota Nicotine Withdrawal Scale (MNWS), Modified Cigarette Evaluation Questionnaire (mCEQ)
- Nicotine metabolites and volatile organic compounds in urine [ Time Frame: Orientation, Study Day 1-3 ]Total nicotine metabolites (nicotine equivalents), NNAL, catecholamines, mercapturic acid, biomarkers of acrolein and propylene oxide, and other volatile organic compounds (VOCs) measured in urine.
- Affect [ Time Frame: Study Day 1-3 ]Positive Affect Negative Affect Schedule (PANAS)
- Withdrawal Symptoms [ Time Frame: Study Day 1-3 ]Minnesota Nicotine Withdrawal Scale (MNWS)
- Skin Temperature [ Time Frame: Study Day 1-3 ]Monitoring of skin temperature
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
| Ages Eligible for Study: | 21 Years to 70 Years (Adult, Older Adult) |
| Sexes Eligible for Study: | All |
| Accepts Healthy Volunteers: | Yes |
Inclusion
- Age ≥21 years ≤ 70 years
- Regular user of tobacco cigarettes (daily or most days)
- Regular user of cannabis in any form (combusted or ingested) at least 5 days out of the month.
- Positive for THC on screening toxicology test
- Willing to abstain from tobacco smoking and all other combustible products (ex: cigars) for 12 hours prior to each outpatient hospital admission.
- Willing to abstain from smoking/ingesting cannabis for 12 hours prior to each outpatient hospital admission.
- Willing to abstain from using any kind of nicotine products for 12 hours prior to each outpatient hospital admission (ex: electronic cigarettes, nicotine replacement therapy).
- Saliva cotinine ≥ 30 ng/mL and/or NicAlert of 6
- Healthy (based on limited physical examination and medical history collected during screening)
- Heart rate < 105 BPM
- Systolic Blood Pressure < 160 and > 90 [considered out of range if both machine and manual readings are above/below these thresholds]
- Diastolic Blood Pressure < 100 and > 50 [considered out of range if both machine and manual readings are above/below these thresholds]
- Body Mass Index ≤ 38.0
Exclusion
- Medical (The following unstable medical conditions):
- Heart disease
- Uncontrolled hypertension
- Thyroid disease (okay if controlled with medication)
- Diabetes
- Hepatitis B or C or Liver disease
- Glaucoma
- Prostatic hypertrophy
- History of paranoia after marijuana use
- Psychiatric conditions
- Current or past schizophrenia, and/or current or past bipolar disorder
- Adult onset ADHD (if being treated)
- Participants with current or past depression and/or anxiety disorders will be reviewed by the study physician and considered for inclusion
- History of psychiatric hospitalizations are not exclusionary, but study participation will be determined as per study physician'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 and are currently abstaining from drug and alcohol
- Positive toxicology test at the screening visit (THC & prescribed medications okay)
- Methadone replacement therapy
- Scoring a 2 or higher on the Severity of Dependence Scale for cannabis use.
- Psychiatric medications
- Current regular use of any psychiatric medications with the exception of SSRIs and SNRIs and current evaluation by the study physician that the participant is otherwise healthy, stable, and able to participate.
- Other Medications
- Use of medications that are inducers of nicotine metabolizing enzyme CYP2A6 (Example: rifampicin, dexamethasone, phenobarbital, and other anticonvulsant drugs).
- Concurrent use of nicotine-containing medications
- Other/Misc. Chronic Health Conditions
- Oral thrush
- Fainting
- Untreated thyroid disease
- Other "life threatening illnesses" as per study physician's discretion
- Use of Other Tobacco Products (OTP); any of the following products in combination more than 15 times in the past month
- smokeless tobacco
- pipes
- cigars, cigarillos
- blunts, spliffs
- Pregnancy
- Pregnancy (self-reported and urine pregnancy test)
- Breastfeeding (determined by self-report)
- Concurrent participation in another clinical trial
- Inability to communicate in English
- Planning to quit smoking or cannabis use within the next 60 days
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02955329
| United States, California | |
| Zuckerberg San Francisco General Hospital - CTSI | |
| San Francisco, California, United States, 94110 | |
| Principal Investigator: | Neal L Benowitz, MD | University of California, San Francisco |
| Responsible Party: | University of California, San Francisco |
| ClinicalTrials.gov Identifier: | NCT02955329 |
| Other Study ID Numbers: |
18-24854 3R01DA039264-02S1 ( U.S. NIH Grant/Contract ) |
| First Posted: | November 4, 2016 Key Record Dates |
| Last Update Posted: | November 10, 2020 |
| Last Verified: | November 2020 |
| Individual Participant Data (IPD) Sharing Statement: | |
| Plan to Share IPD: | No |
| Studies a U.S. FDA-regulated Drug Product: | Yes |
| Studies a U.S. FDA-regulated Device Product: | Yes |
| Device Product Not Approved or Cleared by U.S. FDA: | Yes |
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THC Tobacco Vaping |
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Marijuana Abuse Substance-Related Disorders Chemically-Induced Disorders Mental Disorders Nicotine Ganglionic Stimulants Autonomic Agents |
Peripheral Nervous System Agents Physiological Effects of Drugs Nicotinic Agonists Cholinergic Agonists Cholinergic Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action |