Alcohol and Cannabis Concentrates Co-Administration

NCT ID: NCT05999344

Last Updated: 2025-11-18

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 146 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-12-16
• Study Completion Date: 2024-08-01

Brief Summary

The goal of this study is to learn about the effects of combining alcohol with cannabis concentrate products which contain high levels of THC. The main question[s] it aims to answer are, 1) How does the order in which someone consumes THC and alcohol in a given co-use session impact outcomes such as blood alcohol level, heart rate or subjective drug effects, and 2) how does THC percentage in cannabis influence outcomes following alcohol and cannabis co-administration. Participants will be scheduled for our mobile lab to come to their residence. During the session, they will:

• consume a standardized dose of alcohol as well as use their own preferred cannabis concentrate product.
• they will then remain in our mobile lab for about 4 hours and complete some surveys as well as do some cognitive tasks on an iPad every 30 minutes.
• They will also have their blood drawn three times throughout the session, and will periodically be asked to blood into a breathalyzer to measure blood alcohol level.

Researchers will compare people who use alcohol prior to cannabis to those who use cannabis prior to alcohol to determine whether order of use impacts outcomes.

Detailed Description

Individuals who drink alcohol commonly report co-using cannabis, and the increasing availability of new formulations of highly potent cannabis products on the legal market means that alcohol is likely being combined with cannabis products that contain high levels of delta-9-tetrahydrocannabinol (THC). There is limited existing research on the acute effects of cannabis products containing high amounts of THC, such as cannabis concentrates, which often contain up to 90% THC. Existing laboratory data suggests that consuming alcohol and cannabis together (compared to alcohol alone) is associated with reduced BAC, delayed time to peak blood alcohol concentration (BAC), longer duration of intoxication, and increased subjective intoxication, but it is unknown how cannabis concentrates may interact with alcohol to influence these outcomes. There is also a lack of research regarding whether timing or order of use matters, though recent survey data from our group and others suggests that using alcohol before cannabis may confer additional risk compared to using cannabis prior to alcohol. The present study leverages a federally-compliant mobile laboratory design to explore the acute effects of self-administered cannabis concentrates alongside a standardized dose of alcohol. The investigators will recruit a community sample of individuals who regularly use alcohol and cannabis to participate study sessions in our mobile laboratory. The sessions will involve individuals consuming cannabis concentrates of their choice (that they acquire themselves) along with a standardized dose of alcohol. Half of the participants will use the alcohol before cannabis, and the other half will use the cannabis before alcohol. The investigators will measure intoxication and biological outcomes every 30 minutes for 4 hours. The investigators will also measure differences between those who used alcohol before cannabis and those who used cannabis before alcohol.

Conditions

Alcohol Use Disorder; Cannabis Use

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Alcohol before Cannabis

Participants are randomly assigned to receive the standardized alcohol dose during the experimental session prior to going inside their residence to self-administer their preferred cannabis concentrate product.

Group Type: EXPERIMENTAL

commercially available alcohol administered prior to commercially available cannabis

Intervention Type: OTHER

Researcher administered alcohol prior to self-administration of cannabis

Cannabis before alcohol

Participants are randomly assigned to go inside their residence to self-administer their preferred cannabis concentrate product and then receive the standardized alcohol dose.

Group Type: EXPERIMENTAL

commercially available cannabis administered prior to commercially available alcohol

Intervention Type: OTHER

Self administration of cannabis prior to researcher administered alcohol

Interventions

commercially available cannabis administered prior to commercially available alcohol

Self administration of cannabis prior to researcher administered alcohol

Intervention Type: OTHER

commercially available alcohol administered prior to commercially available cannabis

Researcher administered alcohol prior to self-administration of cannabis

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. 21-65 years old,

2. Heavy drinkers (for men, >4 drinks in one occasion, or >14 drinks per week; for women, >3 drinks in one occasion, or >7 drinks per week)

3. Regular users of legal-market cannabis (at least 3x/week in past 3 months)

4. Have experience using cannabis concentrates within the last year

5. Willing to obtain a concentrate product of their choice for use in the study.

Exclusion Criteria

1. Diagnosed with or seeking treatment for alcohol use disorder (AUD) or other substance use disorder (SUD)

2. Pregnant, breastfeeding or trying to become pregnant

3. Meet criteria for psychotic, bipolar or major depressive disorder with suicidal ideation, or history of these disorders

4. Current use of psychotropic (except anti-depressants) or steroid medications

5. Report illicit drug use in past 60-days or fail drug screen (drug screen tests for the presence of amphetamines, benzodiazepines, cocaine, THC, methamphetamine and opioids; only THC is allowed to be present in urine in order to be eligible to participate in the study

6. Major medical condition contraindicating alcohol and/or cannabis consumption (e.g., liver disease, heart disease, or being told by a doctor that it is unsafe to consume alcohol or cannabis due to a medical condition)

7. Have participated in another research study in the past 8 weeks.

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Institute of Cannabis Research, Colorado State University Pueblo

UNKNOWN

Sponsor Role: collaborator

Colorado State University

OTHER

Sponsor Role: collaborator

University of Colorado, Denver

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Hollis C Karoly, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Colorado, Denver

Locations

Colorado State University

Fort Collins, Colorado, United States

Countries

United States

Other Identifiers

2161

Identifier Type: -

Identifier Source: org_study_id