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Effects of Cannabis/Alcohol on Driving Performance and Field Sobriety Tests

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ClinicalTrials.gov Identifier: NCT05273658
Recruitment Status : Not yet recruiting
First Posted : March 10, 2022
Last Update Posted : July 8, 2022
Sponsor:
Information provided by (Responsible Party):
Thomas D. Marcotte, PhD, University of California, San Diego

Brief Summary:
The overarching aim of this study is to examine the impact of acute cannabis and alcohol administration on driving performance, as well as identify methods for detecting driving under the influence of these substances. One-hundred twenty-five healthy volunteers will be randomized into one of 5 conditions; those who receive 1) low dose alcohol and placebo cannabis, 2) low dose alcohol and tetrahydrocannabinol (THC), 3) high dose alcohol and placebo cannabis, 4) placebo alcohol and THC, and 5) double placebo. Cannabis inhaled ad libitum and/or ingested alcohol will take place at the beginning of the day followed by the completion of driving simulations, components of the Drug Recognition Expert (DRE) evaluations, and bodily fluid draws (e.g., blood, oral fluid/saliva, breath) over the subsequent 4 hours after ingestion. The purpose of this study is to determine (1) the impact of Δ9-THC on driving performance with and without concurrent alcohol ingestion (2) the duration of driving impairment in terms of hours from initial use, (3) the relationship between performance on the DRE measures and cannabis/alcohol ingestion, and 4) if saliva or expired air can serve as a useful adjunct to the field for blood sampling.

Condition or disease Intervention/treatment Phase
Driving Impaired Alcohol Intoxication Driving Under the Influence Cannabis Intoxication Drug: Cannabis Drug: Alcohol Phase 1 Phase 2

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 125 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: Participants will be randomized to smoke a cannabis cigarette containing placebo (.02%) or 18.1% THC, and consume alcohol to achieve a breath alcohol level of .07, .10, or 0.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Masking Description: Cannabis will be dispensed from the Research Pharmacy. Alcohol will be dispensed by a research staff member who is not involved in any assessments. All assessors, investigators, and participants are blinded to the THC and alcohol content.
Primary Purpose: Screening
Official Title: Effects of Cannabis/Alcohol on Driving Performance and Field Sobriety Tests
Estimated Study Start Date : August 2022
Estimated Primary Completion Date : June 2023
Estimated Study Completion Date : June 2023

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Marijuana
Drug Information available for: Ethanol

Arm Intervention/treatment
Placebo Comparator: Placebo
Placebo cannabis and placebo alcohol
Drug: Cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: Marijuana

Drug: Alcohol
Participants will ingest alcohol to achieve the target breath alcohol level

Experimental: Cannabis, No alcohol
18.16% THC, placebo alcohol
Drug: Cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: Marijuana

Drug: Alcohol
Participants will ingest alcohol to achieve the target breath alcohol level

Experimental: Cannabis, Low dose alcohol
18.16% THC, .07 breath alcohol concentration
Drug: Cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: Marijuana

Drug: Alcohol
Participants will ingest alcohol to achieve the target breath alcohol level

Experimental: Placebo cannabis, High dose alcohol
<.1% THC, .10 Breath alcohol concentration
Drug: Cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: Marijuana

Drug: Alcohol
Participants will ingest alcohol to achieve the target breath alcohol level

Experimental: Placebo cannabis, Low dose alcohol
<.1% THC, .07 breath alcohol concentration
Drug: Cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: Marijuana

Drug: Alcohol
Participants will ingest alcohol to achieve the target breath alcohol level




Primary Outcome Measures :
  1. Composite Drive Score [ Time Frame: Participants are assessed pre-smoking/drinking, and then approximately 30 minutes, 1 hour 30 minutes, and 3 hours 30 minutes post-smoking ]

    The Composite Drive Score (CDS) is a z-score comprised of key variables from the simulator tasks (SDLP, speed deviation, and task accuracy during the modified Surrogate Reference Task (mSuRT); coherence from the car following task). This outcome reflects the change in CDS from the pre-smoking assessment, at each timepoint.

    The z-score indicates the number of standard deviations away from the mean from the baseline performance for the entire group. A Z-score of 0 is equal to the mean of a reference population (in this case the pre-smoking performance for the entire group).

    Higher z-scores at each timepoint indicate worse performance (variables that went in the opposite direction were reflected in order to have all variables have the same direction). When examining the change in Composite Drive Score (this outcome variable), a higher score indicates a decline in performance (e.g., Time 2 minus Time1).



Secondary Outcome Measures :
  1. DRE Impairment [ Time Frame: Approximately 1.5 hours and 2.5 hours after alcohol/cannabis administration ]
    DRE officers' determination regarding participant impairment

  2. Whole blood THC concentration [ Time Frame: Approximately 30 minutes after alcohol/cannabis administration ]
    Whole blood THC concentrations determine via LC-MS-MS

  3. Oral Fluid THC concentration [ Time Frame: Approximately 30 minutes after alcohol/cannabis administration ]
    Oral fluid THC concentrations determine via LC-MS-MS

  4. Breath THC concentration [ Time Frame: Approximately 30 minutes after alcohol/cannabis administration ]
    Breath THC concentrations determine via LC-MS-MS



Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Aged 21 to 55
  • Must be a licensed driver and driven a minimum of 1,000 miles in the past year
  • Experience with cannabis and alcohol

Exclusion Criteria:

  • At the discretion of the examining physician, individuals with significant cardiovascular, hepatic or renal disease, uncontrolled hypertension, and chronic pulmonary disease (eg, asthma, COPD) will be excluded.
  • Unwillingness to abstain from cannabis for 2 days prior to screening and experimental visits
  • Positive pregnancy test
  • A positive result on toxicity screening for cocaine, amphetamines, opiates, and phencyclidine (PCP) will exclude individuals from participation.
  • Unwilling to refrain from driving or operating heavy machinery after consuming study medication.
Publications of Results:

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Responsible Party: Thomas D. Marcotte, PhD, Professor, University of California, San Diego
ClinicalTrials.gov Identifier: NCT05273658    
Other Study ID Numbers: 192048
First Posted: March 10, 2022    Key Record Dates
Last Update Posted: July 8, 2022
Last Verified: July 2022

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Thomas D. Marcotte, PhD, University of California, San Diego:
Cannabis
Alcohol
Driving
Additional relevant MeSH terms:
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Marijuana Abuse
Alcoholic Intoxication
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Alcohol-Related Disorders