Ethanol + Cannabinoid Effects on DUI

(THC-ETOH Trial)

Overseen By Chloe Ouchida, BA

Age: 18 - 65

Sex: Any

Trial Phase: Phase 1

Sponsor: Yale University

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

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how alcohol and cannabinoids, such as THC from cannabis, affect driving and thinking skills. Participants will receive either active delta-9-THC, alcohol, both, or a placebo to assess the impact on simulated driving. This trial suits individuals who have previously tried both cannabis and alcohol. For those curious about how these substances might alter driving abilities, this presents an interesting opportunity. As a Phase 1 trial, the research focuses on understanding how these substances work in people, offering a unique chance to contribute to this knowledge.

Do I need to stop taking my current medications for this trial?

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

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that both delta-9-THC (a compound in cannabis) and alcohol significantly affect the body. Studies indicate that delta-9-THC can slow reaction time, impair coordination, and alter perception, which are crucial for activities like driving. These effects can sometimes lead to reduced mental functioning and poorer driving skills.

For alcohol, research consistently shows it greatly impairs driving abilities. Drinking alcohol raises the risk of car accidents, especially as blood alcohol concentration (BAC) levels increase. Using both delta-9-THC and alcohol together increases these risks more than using either one alone, as their combined effects cause greater impairment.

This trial is in its first phase, focusing on the safety of these treatments. While existing information covers each substance separately, this study will examine their combined effects. Treatments reaching this stage are generally considered somewhat safe, but this study aims to gather more detailed information. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about exploring the effects of combining active delta-9-THC and ethanol on driving under the influence (DUI) because it targets interactions between cannabinoids and alcohol, which are commonly used substances. Unlike traditional DUI studies that often focus on a single substance, this trial examines how these two substances together might impair driving skills differently than when used alone. This approach could lead to a better understanding of how combined substance use impacts driving, potentially influencing future safety guidelines and interventions.

What evidence suggests that this trial's treatments could be effective for DUI?

This trial will examine the effects of cannabis and alcohol on driving ability. Research has shown that both substances can impair driving skills. For cannabis, studies indicate that driving skills typically return to normal about 5 to 7 hours after use, although individuals often feel they must try harder to drive safely while under its influence. Alcohol is well-known for greatly increasing the risk of car accidents. Combining alcohol and cannabis often makes driving even more dangerous than using either substance alone. These findings underscore the risks of driving after using these substances. Participants in this trial will be assigned to different groups to assess the effects of active THC, active ethanol, or their combination on driving performance. ^{4 5 6 7 8}

Are You a Good Fit for This Trial?

This trial is for men and women aged 21 to 55 who have used cannabis and alcohol at least once. They must be able to understand and agree to the study's terms. Pregnant individuals, those who've never consumed alcohol or cannabis, or people with hearing problems cannot participate.

Inclusion Criteria

I am between 21 and 55 years old.

Exposed to alcohol at least once

Exposed to cannabis at least once

Exclusion Criteria

I have hearing problems.

Cannabis naive

Positive pregnancy screen

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants receive ethanol and/or THC to study their effects on simulated driving and cognition

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

1-2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Active delta-9-THC
• Active Ethanol

Trial Overview The study aims to assess how ethanol (alcohol) and cannabinoids (like THC from cannabis) affect simulated driving performance and cognitive functions related to driving. Participants will receive either a placebo, active THC, or active ethanol during the trial.

How Is the Trial Designed?

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

Who Is Running the Clinical Trial?

Yale University

Lead Sponsor

Trials

1,963

Recruited

3,046,000+

Published Research Related to This Trial

The study found that combining ethanol and marihuana significantly worsened psychomotor performance, particularly skills needed for driving, indicating an additive or synergistic effect on impairment.

Interestingly, taking ethanol before smoking marihuana did not significantly affect subjective feelings of intoxication, heart rate, or THC levels in the blood, suggesting that the combination primarily impacts performance rather than subjective experiences.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Interaction between marihuana and ethanol: effects on psychomotor performance. Perez-Reyes, M., Hicks, RE., Bumberry, J., et al.[2019]

High doses of cannabis significantly impaired driving performance more than lower doses, while alcohol had minimal effects and did not enhance impairment when combined with cannabis.

Both substances increased speed and variability in driving, but high-dose cannabis led to decreased mean speed and longer reaction times, highlighting the need for further research on their individual effects on driving safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of cannabis and alcohol on simulated arterial driving: Influences of driving experience and task demand. Lenné, MG., Dietze, PM., Triggs, TJ., et al.[2022]

The study of 589 drivers showed that while blood THC concentration is related to specific physical signs like conjunctival injection and pupil dilation, it does not correlate with most clinical tests for impairment.

When THC and ethanol are present together, the risk of being judged impaired significantly increases, indicating that their combined effects on driving ability are greater than either substance alone.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impairment due to cannabis and ethanol: clinical signs and additive effects. Bramness, JG., Khiabani, HZ., Mørland, J.[2019]

This study will assess the effects of both oral and vaporized cannabis on driving performance, cognitive abilities, and field sobriety in healthy adults, involving 64 participants across two double-blind, placebo-controlled trials.

By examining the impact of cannabis alone and in combination with alcohol, the research aims to enhance understanding of impairment levels, which could influence public policy and law enforcement standards regarding cannabis and alcohol use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of oral and vaporized cannabis alone, and in combination with alcohol, on driving performance using the STISIM driving simulator: A two-part, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory protocol. Zamarripa, CA., Novak, MD., Weerts, EM., et al.[2023]

Vaporizing cannabis significantly increases blood levels of THC and its active metabolite 11-OH-THC, especially when combined with low-dose alcohol, which may lead to greater impairment in driving performance.

In a study of 32 adult cannabis smokers, those who consumed alcohol before vaporizing cannabis showed higher maximum blood concentrations of THC, suggesting that the combination of these substances could enhance impairment and should be carefully considered in driving-related regulations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Controlled Cannabis Vaporizer Administration: Blood and Plasma Cannabinoids with and without Alcohol. Hartman, RL., Brown, TL., Milavetz, G., et al.[2019]

A daily dose of 40 mg of rimonabant for 15 days effectively reduced the physiological effects of smoked cannabis, such as tachycardia, similar to a single higher dose of 90 mg on the first day of treatment.

While the 40 mg dose significantly decreased subjective effects of cannabis on day 8, it did not maintain this effect by day 15, indicating that repeated dosing may not consistently reduce the subjective experience of cannabis effects over time.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Single and multiple doses of rimonabant antagonize acute effects of smoked cannabis in male cannabis users. Huestis, MA., Boyd, SJ., Heishman, SJ., et al.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7282977/

Driving Under the Influence of Alcohol Over 30% of motor vehicle traffic fatalities were caused by alcohol-impaired driving, resulting in 10,874 lives lost and $44 billion costs incurred in 2017 ...

2. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0001457523004967

Impact of alcohol driving-while-impaired license ... This study aimed to 1) examine the association between type of recent alcohol-DWI suspension and having a secondary alcohol-related license outcome and/or ...

3. substanceabusepolicy.biomedcentral.com substanceabusepolicy.biomedcentral.com/articles/10.1186/s13011-015-0007-4

Driving under the influence of alcohol: frequency, reasons ... Results showed around 60% of respondents believe that driving under the influence of alcohol is maximum risk behavior. Nevertheless, 90.2% of ...

4. cdc.gov cdc.gov/mmwr/preview/mmwrhtml/mm6448a1.htm

Driving Under the Influence of Alcohol, Marijuana, and ... During 2002–2014, the prevalence of driving under the influence of alcohol alone significantly declined by 59% among persons aged 16–20 years ( ...

5. iihs.org iihs.org/research-areas/alcohol-and-drugs

Alcohol and drugs At a BAC of 0.08% compared with a zero BAC, the likelihood of involvement in a fatal crash is 10 times as high among 16-20 year-old drivers, 7 times as high ...

6. nhtsa.gov nhtsa.gov/risky-driving/drunk-driving

Drunk Driving | Statistics and Resources In 2023, there were 2,117 people killed in alcohol-related crashes where a driver had a BAC of .01 to .07 g/dL. BAC is measured with a breathalyzer, a device ...

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/37186642/

Alcohol and driving-How bad is the combination? A meta ... The effect of BAC on crash and injury risk and culpability is stronger at higher BAC levels and for more serious outcomes.

8. cdc.gov cdc.gov/impaired-driving/facts/index.html

Impaired Driving Facts In 2020, 11,654 people were killed in motor vehicle crashes involving alcohol-impaired drivers, accounting for 30% of all traffic-related deaths ...