Ethanol + Cannabis Effects on DUI

(THC-ETOH-II Trial)

Age: 18 - 65

Sex: Any

Trial Phase: Phase 1

Sponsor: Yale University

Disqualifiers: Cannabis naïve, Alcohol naïve, Pregnancy, Hearing deficits

Compensation: Varies

Number of Visits: 2

Duration: 1 day

40 Participants Needed

Trial Summary

What is the purpose of this trial?

The overarching goal of this study is to characterize the effects of ethanol and cannabinoids on simulated driving and related cognition.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the drug combination of cannabis and alcohol?

Some studies suggest that CBD, a component of cannabis, may help reduce alcohol consumption and protect against alcohol-related harm, like liver and brain damage. However, combining cannabis and alcohol can impair driving skills more than using either alone, and the effects vary between individuals. ^{1 2 3 4 5}

Is it safe to use cannabis and alcohol together?

Using cannabis and alcohol together can impair driving skills more than using either alone, increasing the risk of accidents. Cannabis and alcohol can both affect your ability to drive safely, and combining them can make it harder to compensate for these effects. It's important to be cautious and avoid driving after using these substances. ^{2 4 5 6 7}

How does the drug combination of ethanol and cannabis differ from other treatments for DUI?

This drug combination is unique because it explores the synergistic effects of very low doses of ethanol and cannabis, which have not been extensively tested in humans. Unlike other treatments, this study focuses on how these substances interact to potentially impair memory and cognitive functions, which are critical for driving. ^{1 2 8 9 10}

Eligibility Criteria

This trial is for men and women aged 21-55 who occasionally use cannabis and have had at least two alcoholic drinks at some point. They must be able to consent to the study. People can't join if they've never used cannabis or alcohol, are pregnant, or have hearing problems.

Inclusion Criteria

Occasional current cannabis users

Experience with drinking 2 or more standard drinks of alcohol at least once in lifetime

Able to provide informed consent

Exclusion Criteria

Cannabis naïve

Alcohol naïve

Positive pregnancy screen

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants receive oral ethanol and vaporized cannabis to study their effects on simulated driving and cognition

1 day

1 visit (in-person)

Cognitive Testing

Participants undergo cognitive tests to assess the effects of alcohol and THC on driving-related cognition

Approximately 4 hours

1 visit (in-person)

Follow-up

Participants are monitored for any delayed effects of the substances administered

1 week

Treatment Details

Interventions

• Cannabis
• Ethanol

Trial Overview The study aims to understand how drinking alcohol (ethanol) and inhaling cannabis affect simulated driving and thinking skills. Participants will receive either a placebo, actual ethanol, or active inhaled cannabis to compare their effects.

Participant Groups

Group I: Placebo THC and Active Ethanol Experimental Treatment 2 Interventions

Group II: Active THC and Placebo Ethanol Experimental Treatment 2 Interventions

Group III: Active THC and Active Ethanol Experimental Treatment 2 Interventions

Group IV: Placebo THC and Placebo Ethanol Placebo Group 1 Intervention

Cannabis is already approved in Canada, United States, European Union for the following indications:

Approved in Canada as Cannabis for:

• Chronic pain
• Nausea and vomiting associated with chemotherapy
• Spasticity associated with multiple sclerosis

Approved in United States as Cannabis for:

• Seizures associated with Lennox-Gastaut syndrome and Dravet syndrome
• Nausea and vomiting associated with chemotherapy

Approved in European Union as Cannabis for:

• Spasticity associated with multiple sclerosis
• Chronic pain

Who Is Running the Clinical Trial?

Yale University

Lead Sponsor

Trials

1,963

Recruited

3,046,000+

Findings from Research

In a study of injured drivers presenting to emergency departments in cannabis-legal states, 8% reported cannabis use within 8 hours before a motor vehicle collision (MVC), but biosample testing revealed a higher prevalence of 18%.

High-risk crash features were prevalent among drivers using cannabis, whether alone or with alcohol; however, seriously injured patients were less likely to report cannabis use compared to alcohol use, indicating potential differences in the impact of these substances on crash severity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cannabis presentations to the emergency department after MVC in the era of legalization for recreational use. Choo, EK., Nishijima, D., Trent, S., et al.[2022]

Preliminary studies suggest that cannabidiol (CBD) may reduce alcohol consumption and protect against some harmful effects of alcohol, such as liver and brain damage, based on both preclinical and limited human research.

However, there is a lack of comprehensive studies on the interactions between CBD and alcohol in humans, making it difficult to draw definitive conclusions about their combined effects and potential therapeutic implications for alcohol use disorder.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of cannabidiol on alcohol-related outcomes: A review of preclinical and human research. Nona, CN., Hendershot, CS., Le Foll, B.[2019]

In a study involving 10 healthy volunteers, CBD alone did not impair motor or psychomotor performance, while alcohol significantly did, indicating that CBD may not negatively affect cognitive functions on its own.

When combined with alcohol, CBD resulted in lower blood alcohol levels compared to alcohol alone, suggesting that CBD may mitigate some effects of alcohol, although the overall impairments in performance remained similar.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Interaction of cannabidiol and alcohol in humans. Consroe, P., Carlini, EA., Zwicker, AP., et al.[2019]

Cannabis and alcohol both impair driving skills, but cannabis effects vary more between individuals due to factors like tolerance and smoking technique, while alcohol consistently increases crash risk.

Combining cannabis with alcohol significantly worsens driving impairment compared to using either substance alone, highlighting the need for caution and advising cannabis users to wait several hours before driving.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of cannabis compared with alcohol on driving. Sewell, RA., Poling, J., Sofuoglu, M.[2022]

In a survey of 533 cannabis users who drink alcohol, those using cannabis to treat a medical condition reported drinking less frequently than those who do not use cannabis for treatment.

The type of cannabis used affects alcohol consumption; individuals using high-THC/CBD cannabis tended to drink more on days they used cannabis compared to those using medium or low-THC/CBD cannabis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Investigating Relationships Between Alcohol and Cannabis Use in an Online Survey of Cannabis Users: A Focus on Cannabinoid Content and Cannabis for Medical Purposes. Karoly, HC., Mueller, RL., Andrade, CC., et al.[2021]

Alcohol use significantly increases the risk of injury, with a relative risk of 3.00 for those who consumed alcohol within six hours prior to injury, indicating a strong dose-response relationship.

Interestingly, cannabis use was associated with a lower risk of injury (relative risk of 0.33), suggesting a potential protective effect, although this finding should be interpreted cautiously due to the small number of cannabis users in the study.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Alcohol and cannabis use as risk factors for injury--a case-crossover analysis in a Swiss hospital emergency department. Gmel, G., Kuendig, H., Rehm, J., et al.[2022]

A significant portion of cannabis products (58.5%) lacked information on CBD content, and most products (72-100%) with CBD fell into the highly intoxicating THC:CBD ratio category (≥1:1), suggesting that patients may experience enhanced acute effects and intoxication.

Medical and recreational cannabis products are largely similar, posing a risk for patients seeking therapeutic benefits, as they may inadvertently consume high-potency products that lead to unwanted side effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Potency and Therapeutic THC and CBD Ratios: U.S. Cannabis Markets Overshoot. Pennypacker, SD., Cunnane, K., Cash, MC., et al.[2022]

In a study involving 11 healthy volunteers, very low doses of ethanol and THC were tested in combination, but the results showed no evidence of synergistic effects on cognitive performance or subjective responses.

The combined effects of these substances were not stronger than their individual effects, and in some cases, they were even less effective when taken together.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Combined effects of acute, very-low-dose ethanol and delta(9)-tetrahydrocannabinol in healthy human volunteers. Ballard, ME., de Wit, H.[2021]

In a study with alcohol-preferring rats, combining ethanol and THC significantly impaired memory in an object recognition task, highlighting the risks of co-abusing these substances.

The memory impairment was linked to the activation of CB1 receptors, as a specific antagonist reversed the effects of THC, indicating a potential mechanism for the observed synergistic action between ethanol and THC.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Memory impairment following combined exposure to delta(9)-tetrahydrocannabinol and ethanol in rats. Ciccocioppo, R., Antonelli, L., Biondini, M., et al.[2019]

In a study of 120 adults, those using cannabis with predominantly CBD consumed significantly fewer alcoholic drinks and had fewer drinking days compared to those using cannabis with predominantly THC or a combination of CBD and THC.

These results suggest that CBD may help reduce alcohol consumption, supporting previous preclinical findings and highlighting the importance of cannabinoid content in understanding alcohol and cannabis co-use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

THC and CBD effects on alcohol use among alcohol and cannabis co-users. Karoly, HC., Mueller, RL., Andrade, CC., et al.[2021]

References

1. United States pubmed.ncbi.nlm.nih.gov

Cannabis presentations to the emergency department after MVC in the era of legalization for recreational use. [2022]

2. United States pubmed.ncbi.nlm.nih.gov

Effects of cannabidiol on alcohol-related outcomes: A review of preclinical and human research. [2019]

3. Germany pubmed.ncbi.nlm.nih.gov

Interaction of cannabidiol and alcohol in humans. [2019]

4. England pubmed.ncbi.nlm.nih.gov

The effect of cannabis compared with alcohol on driving. [2022]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Investigating Relationships Between Alcohol and Cannabis Use in an Online Survey of Cannabis Users: A Focus on Cannabinoid Content and Cannabis for Medical Purposes. [2021]

6. England pubmed.ncbi.nlm.nih.gov

Alcohol and cannabis use as risk factors for injury--a case-crossover analysis in a Swiss hospital emergency department. [2022]

7. Switzerland pubmed.ncbi.nlm.nih.gov

Potency and Therapeutic THC and CBD Ratios: U.S. Cannabis Markets Overshoot. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Combined effects of acute, very-low-dose ethanol and delta(9)-tetrahydrocannabinol in healthy human volunteers. [2021]

9. Netherlands pubmed.ncbi.nlm.nih.gov

Memory impairment following combined exposure to delta(9)-tetrahydrocannabinol and ethanol in rats. [2019]

10. United States pubmed.ncbi.nlm.nih.gov

THC and CBD effects on alcohol use among alcohol and cannabis co-users. [2021]