THC Crossover Study

NCT ID: NCT04429568

Last Updated: 2024-07-01

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

14 participants

Study Classification

INTERVENTIONAL

Study Start Date

2020-10-30

Study Completion Date

2024-06-25

Brief Summary

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This is a randomized, crossover study enrolling experienced dual cannabis-tobacco smokers (N=18) to describe the differences in THC and toxicant exposure, examining pharmacokinetic, subjective, and cardiovascular effects from smoking and vaping dry herb cannabis. This study will also examine the differences in toxicant exposure and cardiovascular disease risk between smoking cannabis and smoking tobacco cigarettes.

Detailed Description

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Experienced dual cannabis-tobacco smokers will participate in a within-subject crossover study with three blocks: smoked cannabis (purchased by participants from a local dispensary), dry herb cannabis vaporizer, and usual brand tobacco cigarette. Each block will consist of 2 consecutive days on an inpatient research ward. The first inpatient day of each block will comprise of two sessions: (1) The first session will be a standardized bout to compare pharmacokinetic, physiologic, and subjective effects of cannabis and tobacco use; (2) after 6 hours of abstinence, the second session will be ad libitum access to the assigned product for 2 hours to compare subjective effects (reward, satisfaction, craving reduction) and use patterns. The second inpatient day will consist of ad libitum use of the assigned product from 8:00 in the morning to midnight. An abstinence day will be added after the second day of the last block to assess exposure and effects biomarkers during a period of abstinence from cannabis (smoked/vaped) or tobacco.

Conditions

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THC Cannabis Cannabis Smoking Cannabis Use, Unspecified Cigarette Smoking Tobacco Use Nicotine Dependence Nicotine Withdrawal Cardiovascular Risk Factor

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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Smoked Cannabis, Vaped Cannabis, or Tobacco Cigarette

* Abstinence from any product night before hospital admission
* Standardized Session of assigned product: smoked cannabis, vaped cannabis, or tobacco cigarette
* 6-hr abstinence and blood draws (PK)
* 2 hr Free use session w/ video monitoring
* Free use of assigned product
* 12-hr cardiovascular (CV) monitoring
* Circadian blood draws
* 12-hr urine collection

Group Type OTHER

Smoked Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff.

Vaped Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff. All participants will use the study-provided PAX® (PAX 2) dry herb vaporizer, one of the most popular handheld vaporizers.

Tobacco Cigarette

Intervention Type OTHER

Tobacco cigarettes of participants' choice (usual brand) will be provided by research staff for use on the study.

Either of the 2 remaining products

* Abstinence from any product night before hospital admission
* Standardized Session of assigned product: smoked cannabis, vaped cannabis, or tobacco cigarette
* 6-hr abstinence and blood draws (PK)
* 2 hr Free use session w/ video monitoring
* Free use of assigned product
* 12-hr CV monitoring
* Circadian blood draws
* 12-hr urine collection

Group Type OTHER

Smoked Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff.

Vaped Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff. All participants will use the study-provided PAX® (PAX 2) dry herb vaporizer, one of the most popular handheld vaporizers.

Tobacco Cigarette

Intervention Type OTHER

Tobacco cigarettes of participants' choice (usual brand) will be provided by research staff for use on the study.

Remaining product

* Abstinence from any product night before hospital admission
* Standardized Session of assigned product: smoked cannabis, vaped cannabis, or tobacco cigarette
* 6-hr abstinence and blood draws (PK)
* 2 hr Free use session w/ video monitoring
* Free use of assigned product
* 12-hr CV monitoring
* Circadian blood draws
* 12-hr urine collection

Group Type OTHER

Smoked Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff.

Vaped Cannabis

Intervention Type OTHER

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff. All participants will use the study-provided PAX® (PAX 2) dry herb vaporizer, one of the most popular handheld vaporizers.

Tobacco Cigarette

Intervention Type OTHER

Tobacco cigarettes of participants' choice (usual brand) will be provided by research staff for use on the study.

Interventions

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Smoked Cannabis

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff.

Intervention Type OTHER

Vaped Cannabis

Cannabis will be purchased by the participants and reimbursed the full cost by the study. Participants will be asked to purchase enough to last 2 full days of use. To reduce variability between products, participants will be asked to purchase cannabis from one dispensary near the research facility (Purple Star MD at 2520 Mission St., San Francisco). Receipt must be provided to study staff. All participants will use the study-provided PAX® (PAX 2) dry herb vaporizer, one of the most popular handheld vaporizers.

Intervention Type OTHER

Tobacco Cigarette

Tobacco cigarettes of participants' choice (usual brand) will be provided by research staff for use on the study.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Healthy on the basis of medical history and limited physical examination, as described below:

Heart rate \< 105 beats per minute (BPM); Systolic Blood Pressure \< 160 and \> 90\*; Diastolic Blood Pressure \< 100 and \> 50\*

\*Considered out of range if both machine and manual readings are above/below these thresholds.

* Current regular user of cannabis who smokes cannabis as joint or blunt at least 3 times a week for past 3 months
* History of cannabis vaporizer use or willingness to use the vaporizer in the study
* Current tobacco cigarette use who smokes ≥ 5 cigarettes per day
* Saliva cotinine ≥ 50 ng/ml
* Test positive for D-9-tetrahydrocannabinol (THC) at screening and self-report of cannabis use

Exclusion Criteria

* 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

* Psychiatric conditions:

Current or past schizophrenia, and/or current or past bipolar disorder; Adult onset attention deficit hyperactivity disorder (ADHD); 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

* Concurrent regular use of smokeless tobacco or pipes \[occasional users of these products may be enrolled if they agree to abstain from their use during the period of the study\]
* 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; Psychiatric medications: current regular use of any psychiatric medications with the exception of Selective Serotonin Reuptake Inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) and current evaluation by the study physician that the participant is otherwise healthy, stable, and able to participate.

* Other/Misc. Chronic Health Conditions:

Oral thrush; Fainting; Untreated thyroid disease; Other "life threatening illnesses" as per study physician's discretion

* Pregnancy:

Pregnancy (self-reported and urine pregnancy test); Breastfeeding (determined by self-report)

* 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 at the screening visit (THC \& prescribed medications okay); Methadone replacement therapy

* Concurrent participation in another clinical trial
* Inability to communicate in English
* History of marijuana-induced psychosis or paranoia after smoking marijuana
* Scoring a 2 or higher on the Severity of Dependence Scale for cannabis use
* Planning to quit smoking or vaping within the next 60 days
Minimum Eligible Age

21 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Tobacco Related Disease Research Program

OTHER

Sponsor Role collaborator

University of California, San Francisco

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Gideon St. Helen, PhD

Role: PRINCIPAL_INVESTIGATOR

University of California, San Francisco

Locations

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Zuckerberg San Francisco General Hospital

San Francisco, California, United States

Site Status

University of California, San Francisco

San Francisco, California, United States

Site Status

Countries

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United States

Other Identifiers

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17-24117

Identifier Type: -

Identifier Source: org_study_id

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