Cannabis + Alcohol on Impairment

Overseen By Tory Spindle, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Phase 1

Sponsor: Johns Hopkins University

Must not be taking: Psychoactive drugs, OTC drugs

Disqualifiers: Significant medical condition, Psychiatric condition, Severe alcohol use, others

Compensation: Varies

Number of Visits: 7

Duration: 7 sessions

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how cannabis and alcohol, both alone and together, affect feelings and behaviors. Researchers test different doses to determine how each combination impacts impairment. Participants join one of several groups involving various doses of cannabis and alcohol, or placebos (fake treatments). Those who have used both cannabis and alcohol together at least once in the past year and have experienced binge drinking at least twice in the last 90 days might be a good fit for this study. As a Phase 1 trial, this research focuses on understanding how these substances work in people, offering an opportunity to contribute to groundbreaking insights.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it excludes those using certain drugs or medications that could affect safety. It's best to discuss your specific medications with the trial staff.

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

Research has shown that using cannabis and alcohol together can amplify their effects, leading to more noticeable impairment. One study found that even low doses of cannabis (10mg THC) can cause feelings of being "high" or paranoid, even without alcohol. Mixing cannabis with alcohol can intensify these feelings, increasing impairment and potentially leading to risky behaviors or accidents.

High doses of cannabis (25mg THC) can cause short-term issues like paranoia or temporary mental problems. These effects worsen when combined with even small amounts of alcohol, possibly causing dizziness or nausea. People may also behave unusually when using both substances together.

Overall, combining cannabis and alcohol increases the risk of dizziness, sweating, or nausea. It is important to be aware of these risks when considering participation in a clinical trial involving these substances. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about this trial because it explores how cannabis and alcohol interact to affect impairment, which is not well understood. Unlike traditional studies that focus on alcohol or cannabis alone, this investigation looks at how different doses of THC and alcohol together influence cognitive and motor functions. The trial includes unique combinations, such as high dose cannabis with low dose alcohol, to see how varying levels impact impairment. By understanding these interactions, the trial could provide insights into safer consumption guidelines and inform public health recommendations.

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

Research shows that using cannabis and alcohol together impairs individuals more than using either alone. This trial will explore various combinations of cannabis and alcohol. Participants in different arms will receive either low or high doses of cannabis with either low-dose alcohol or placebo alcohol. Studies have found that this combination severely affects driving skills. Even at low doses, mixing cannabis with alcohol increases feelings of intoxication and stimulation. One study found that high doses of both substances can seriously affect memory and attention. These findings suggest that combining cannabis and alcohol significantly impacts behavior and perception. ^{1 6 7 8 9}

Who Is on the Research Team?

Tory Spindle, PhD

Principal Investigator

Johns Hopkins University

Are You a Good Fit for This Trial?

Participants must be healthy adults aged 21-55, not pregnant or nursing, with a BMI of 19-36 kg/m2. They should have engaged in binge drinking at least twice in the past 90 days and used cannabis within the last year but no more than twice weekly over the past three months.

Inclusion Criteria

I have not donated blood in the last 30 days.

I am between 21 and 50 years old.

Have a body mass index (BMI) in the range of 19 to 36 kg/m2

Exclusion Criteria

Been in treatment previously for alcohol or cannabis use disorder

Psychoactive drug use (aside from cannabis, nicotine, alcohol, or caffeine) in past month

I am not taking any medications or supplements that could affect my safety in the trial.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants complete 7 outpatient drug administration sessions with self-administration of oral cannabis and alcohol

7 sessions

7 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Alcohol
• Cannabis

Trial Overview The study is examining how oral cannabis and alcohol affect people's subjective feelings of impairment and their actual performance on tasks. It will look at these substances both separately and together to understand their combined effects.

How Is the Trial Designed?

Group I: low dose cannabis with placebo alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 10mg THC in combination with a placebo alcohol drink.

Group II: low dose cannabis with low dose alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 10mg THC in combination with an alcohol drink (0.05 percent BAC).

Group III: high dose cannabis with placebo alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 25mg THC in combination with a placebo alcohol drink.

Group IV: high dose cannabis with low dose alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 25mg THC in combination with an alcohol drink (0.05 percent BAC).

Group V: Placebo cannabis + low dose alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 0mg THC in combination with an alcohol drink (0.05 percent BAC).

Group VI: Placebo cannabis + high dose alcohol Experimental Treatment 2 Interventions

Participants administer oral cannabis containing 0mg THC in combination with an alcohol drink (0.08 percent BAC).

Group VII: Placebo cannabis + placebo alcohol Placebo Group 2 Interventions

Participants administer oral cannabis containing 0mg THC in combination with a placebo alcohol drink.

Alcohol is already approved in United States, European Union, Canada, Japan, China, Switzerland for the following indications:

Approved in United States as Ethanol for:

• None (not approved as a therapeutic agent)

Approved in European Union as Ethanol for:

• None (not approved as a therapeutic agent)

Approved in Canada as Ethanol for:

• None (not approved as a therapeutic agent)

Approved in Japan as Ethanol for:

• None (not approved as a therapeutic agent)

Approved in China as Ethanol for:

• None (not approved as a therapeutic agent)

Approved in Switzerland as Ethanol for:

• None (not approved as a therapeutic agent)

Who Is Running the Clinical Trial?

Johns Hopkins University

Lead Sponsor

Trials

2,366

Recruited

15,160,000+

National Institute on Drug Abuse (NIDA)

Collaborator

Trials

2,658

Recruited

3,409,000+

Published Research Related to This Trial

This study aims to investigate the acute effects of co-using cannabis concentrates and alcohol, focusing on how the cannabinoid content and the order of consumption (cannabis before alcohol vs. alcohol before cannabis) influence intoxication levels.

By using a mobile laboratory to measure both objective (like blood cannabinoid levels and psychomotor performance) and subjective intoxication, the research seeks to provide clearer insights that could inform harm-reduction strategies for individuals who use both substances.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Protocol for a mobile laboratory study of co-administration of cannabis concentrates with a standard alcohol dose in humans. Karoly, HC., Prince, MA., Emery, NN., 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]

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 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]

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]

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]

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 of 465,090 U.S. individuals aged 12 to 25, less frequent cannabis use (1-20 days/month) was significantly linked to higher rates of alcohol dependence and various alcohol-related problems, indicating that even occasional cannabis users may be at risk for alcohol use disorders.

The research suggests that both frequent and less frequent cannabis use are associated with serious alcohol-related issues, such as heavy drinking and risky behaviors, highlighting the need for careful consideration of cannabis use in alcohol treatment and policy planning.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Frequency of cannabis use and alcohol-associated adverse effects in a representative sample of U.S. adolescents and youth (2002-2014) a cross-sectional study. Ramadan, MM., Banta, JE., Bahjri, K., et al.[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]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2722956/

THE EFFECT OF CANNABIS COMPARED WITH ... Combining marijuana with alcohol eliminates the ability to use such strategies effectively, however, and results in impairment even at doses which would be ...

2. goodrx.com goodrx.com/well-being/substance-use/mixing-alcohol-and-weed-effects?srsltid=AfmBOorxtiCJ_91U79nMIMeJsTmS6BdRLag1xSgrcgQHj0BKJy6PvKlO

What Happens When You Mix Weed and Alcohol? CBD can make you sleepy, especially at high doses. Alcohol can worsen this side effect, making you feel groggy or disoriented. This can lead to falls or ...

3. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0376871625000481

The association between cannabis and alcohol co-use and ... Co-use of cannabis and alcohol is associated with a higher prevalence of health-related, psychiatric, and psychosocial impairments.

4. healthline.com healthline.com/health/alcohol-and-weed

What Really Happens When You Mix Alcohol and Weed? The researchers reported that combining THC and alcohol consistently impaired driving performance, with worse performance during nighttime ...

5. ncids.org ncids.org/2021/marijuana-impairment-faq/

Marijuana Impairment FAQ “Working memory (PSAT), psychomotor functioning (DSST), and divided attention (DAT) were all negatively impacted after use of the high oral (25 ...

6. addictioncenter.com addictioncenter.com/alcohol/alcohol-marijuana/

Alcohol and Marijuana: Combined Effects and Risks Using alcohol and marijuana together can produce uncomfortable side effects such as dizziness, sweating, and nausea.

7. medicalnewstoday.com medicalnewstoday.com/articles/weed-and-alcohol

What happens when you mix weed and alcohol? Combining weed and alcohol can increase the effects of both drugs and cause adverse reactions. The combination can also lead people to engage in unusual or ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11238947/

The effects of simultaneous alcohol and cannabis use on ... Over 75% of young adults who use cannabis also report drinking alcohol, leading to increased risks including impaired cognition, substance use disorders, and ...

9. nortonhealthcare.com nortonhealthcare.com/news/alcohol-cannabis-blood-pressure/

How alcohol affects your heart, liver and blood pressure Alcohol and cannabis can impact blood pressure and medications. Learn how to make informed choices for heart health and talk openly with your doctor.