Cannabis' Impact on Alcohol Consumption

Brown University

Status and phase: Enrolling; Phase 2

Conditions: Cannabis; Cannabis Use; Alcohol Use Disorder; Alcohol Drinking

Treatments: Drug: THC-dominant cannabis; Drug: CBD-dominant cannabis; Drug: Alcohol; Drug: Alcohol placebo; Drug: Cannabis placebo

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05389930

R01AA029711 (Other Grant/Funding Number)

2022003195

Details and patient eligibility

About

This study employs a repeated measures experimental design to examine the effect of THC-dominant dose of cannabis and CBD-dominant dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo.

The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly.

Full description

This study employs a repeated measures experimental design to examine the effect of THC-dominant (9.53% THC and 0.09% CBD) dose of cannabis and CBD-dominant (0.35% THC and 11.27% CBD) dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo. The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly to obtain the final sample of 200 with complete data. Participants will be tested at a baseline session, during three experimental sessions, and then during a subsequent 4-week period in the natural environment using a smart-phone application. Findings have important implications for cannabis regulatory science and alcohol use disorder treatment by addressing the relative impact of specific cannabinoids as well as contextual risk in cannabis-alcohol co-use.

Enrollment: 350 estimated patients

Sex: All

Ages: 21 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age 21 to 50
• English-speaking
• cannabis smoking in past two months
• heavy drinking in past two months
• in good physical health and weighing < 250 lbs
• zero breath alcohol at each visit

Exclusion criteria

• positive pregnancy test
• nursing
• positive urine toxicology screen for drugs other than cannabis
• interest to quit or receive treatment for cannabis or alcohol use

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Factorial Assignment

Masking: Double Blind

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350 participants in 5 patient groups, including a placebo group

THC-dominant cannabis dose

Experimental group

Description:

367 mg of cannabis plant material with 9.53% THC and 0.09% CBD and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe

Treatment:

Drug: Alcohol placebo

Drug: Alcohol

CBD-dominant cannabis dose

Experimental group

Description:

367 mg of cannabis plant material with 11.27% CBD and 0.35% THC and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe

Treatment:

Drug: Alcohol placebo

Drug: Alcohol

Placebo

Placebo Comparator group

Description:

584 mg of cannabis plant material will be smoked in a handheld pipe

Treatment:

Drug: Alcohol placebo

Drug: Alcohol

Alcohol priming dose

Experimental group

Description:

Alcohol: 0.3 g/kg. Alcohol priming drink is designed to raise blood alcohol levels to 0.03 g/dl and be consumed in 5 minutes. The drink is mixed using 80-proof liquor and juice. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo.

Treatment:

Drug: Cannabis placebo

Drug: CBD-dominant cannabis

Drug: THC-dominant cannabis

Alcohol placebo dose

Placebo Comparator group

Description:

Placebo beverage contains only juice and a negligible trace of alcohol for masking. The weight and sex-adjusted volume of alcohol and non-alcohol containing beverages will be equal. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo.

Treatment:

Drug: Cannabis placebo

Drug: CBD-dominant cannabis

Drug: THC-dominant cannabis