Effects of Inhaled Cannabis on Driving Performance

This study has been completed.
Sponsor:
Collaborators:
NHTSA
Information provided by (Responsible Party):
Gary R Gaffney, University of Iowa
ClinicalTrials.gov Identifier:
NCT01620177
First received: June 4, 2012
Last updated: April 25, 2014
Last verified: April 2014
  Purpose

The purpose of this study is to expand understanding of the effects of cannabis on driving performance with and without the presence of low levels of alcohol.

This project will involve the development a of a protocol and driving environment that is sensitive to the effects of cannabis on driving performance by building on prior driving situations used previously for testing the effects of alcohol on driving.


Condition Intervention
Alcohol Drinking
Cannabis
Drug: Alcohol(oral) and placebo
Drug: Cannabis(THC)(Inhaled) and Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Effects of Inhaled Cannabis on Driving Performance

Resource links provided by NLM:


Further study details as provided by University of Iowa:

Primary Outcome Measures:
  • Driving Performance [ Time Frame: Through entire drive, 0.5-1.1 hr post cannabis administration. ] [ Designated as safety issue: No ]
    Measured by speed, lane position, steering wheel position, reaction time, headway to lead vehicle, eye tracking


Secondary Outcome Measures:
  • Rogers gambling task [ Time Frame: -1.2 hr, 1.5 hr, 3 hr, 5.5, 7.5 hr post cannabis administration ] [ Designated as safety issue: No ]
    Used as an assessment of risk perception, risk taking and impulsivity. Performance on this task as well correlations between cannabinoid concentrations and driving performance and effects on the Rogers gambling task will be measured.

  • Balloon Analogue Risk Task (BART) [ Time Frame: -1.2 hr, 1.5 hr, 3 hr, 5.5, 7.5 hr post cannabis administration ] [ Designated as safety issue: No ]
    BART assesses risk-taking behavior in an objective manner. Performance on this task as well correlations between cannabinoid concentrations and driving performance and effects on the BART will be measured.

  • Subjective effect-Good Drug Effect [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how they feel.Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • THC concentration in plasma sample [ Time Frame: -0.7 hr, 0.25hr, 1.1 hr, 2 hr, 3 hr, 4.5 hr, 6 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Measurement of THC concentration levels in plasma over the course of each visit compared to that of the other visits.

  • THC concentration levels in Whole blood [ Time Frame: -0.7 hr, 0.25hr, 1.1 hr, 2 hr, 3 hr, 4.5 hr, 6 hr, 8 hr post cannabis ] [ Designated as safety issue: No ]
    Measurement of THC concentration levels in whole blood over the course of each visit compared to that of the other visits.

  • Subjective effect-high [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subject's assessment of how high they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Stoned [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subject's assessment of how "stoned" they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Stimulated [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how stimulated they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-sedated [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how sedated they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-anxious [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how anxious they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Restless [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how restless they feel. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-difficulty concentrating [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their ability to concentrate. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Altered sense of time [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their sense of time.Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-slowed speech [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their speech.Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-body feels sluggish/heavy [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of how their body feels. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Feeling of hunger [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their level of hunger. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-thirsty [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their feeling of thirsty. Subjective effects will be used in correlation with driving performance within each visit and across all visits

  • Subjective effect-Shakiness [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their level of shakiness. Subjective effects will be used in correlation with driving performance within each visit and across all visits

  • Subjective effect-nausea [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their level of nausea. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Headache [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their level of headache. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Palpitations [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their feelings of palpitations. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective effect-Upset stomach [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessments of their feeling of stomach being upset. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective Effect-Dizzy [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of their level of dizziness. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • Subjective Effect-Dry mouth/throat [ Time Frame: -0.7 hr, 0.25 hr, 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Subjects' assessment of the saliva in mouth. Subjective effects will be used in correlation with driving performance within each visit and across all visits.

  • THC concentration in Saliva [ Time Frame: -10+ hr, -0.7 hr, 0.25 hr 1.1 hr, 2 hr, 3 hr, 4 hr, 5 hr, 6 hr, 7 hr, 8 hr post cannabis administration ] [ Designated as safety issue: No ]
    Measurement of THC concentration levels in saliva over the course of each visit compared to that of the other visits.


Enrollment: 99
Study Start Date: July 2012
Study Completion Date: March 2014
Primary Completion Date: March 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 0% THC with 0.065 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana
Experimental: 2.5-3.5% THC with 0.065 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana
Experimental: 6.0-7.5% THC and 0.065 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana
Experimental: 2.5-3.5% THC with 0 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana
Experimental: 6.0-7.5% THC with 0 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana
Experimental: 0% THC with 0 g/dL BAC Drug: Alcohol(oral) and placebo
Subjects will be dosed to an approximate peak BAC of 0.065%. Subjects will be tested on the decline such that subjects will be at or above the goal BAC (0.05%) throughout the drive
Other Names:
  • Ethnanol
  • Ethyl Alcohol
Drug: Cannabis(THC)(Inhaled) and Placebo
Cannabis vapor is produced from 500 mg either placebo (0% THC), approximately 2.5-3.5% THC (low dose), or approximately 6.0-7.5% THC (high dose) bulk cannabis plant material to yield doses of approximately 0, 12.5-17.5, or 30-37.5 mg THC
Other Names:
  • Marihuana
  • Marijuana

Detailed Description:

Individuals will be recruited who are currently users of cannabis and alcohol to participate in this study. They will undergo a physical exam at screening. There will be six study visits where the subject will arrive at the Clinical Research Unit(University of Iowa Hospitals & Clinics) the night before dosing. At each visit subjects will be receive one of the following six dosing regimens: placebo alcohol with placebo cannabis; placebo alcohol with low-dose cannabis, placebo alcohol with higher-dose of cannabis, low dose alcohol with placebo cannabis; low dose alcohol with low dose cannabis, low dose alcohol with higher-dose of cannabis. After dosing, participants will have provide saliva samples and blood drawn periodically to check cannabis levels and will complete a driving simulation. After completing the drive, additional saliva samples and blood draws will occur and participants will be monitored until it is safe to transport home.

  Eligibility

Ages Eligible for Study:   21 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy adult (age 21-55) men and women, based on medical and psychological evaluation
  • Currently valid unrestricted (except for vision correction) US driver's license
  • Licensed driver for at least the past two years
  • Drove at least 1300 miles in the past year, by self-report
  • Live within an 80 mile radius of NADS
  • Available for an overnight stay followed by a full-day study session for six sessions
  • Must be considered a light or moderate drinker according to Quantity-Frequency-Variability Scale (QFV)
  • Cannabis use with a minimum frequency averaging at least one day per quarter and no more than three days a week during the three months prior to study entry
  • Peripheral veins suitable for repeated venipuncture and/or placement of an intravenous catheter
  • Systolic blood pressure within a clinically normal range (120 ± 30 mmHg) and -diastolic blood pressure of 80 ± 20 mmHg..
  • Good command of written and spoken English
  • Female subjects with reproductive potential must agree to use (and/or have their partner use) one (1) acceptable method of birth control beginning at the screening visit throughout the study (including intervals between treatment periods/panels) and until 2 weeks after the last dose of study drug in the last treatment period. Acceptable methods of birth control include the following: intrauterine device (IUD-with or without local hormone release), diaphragm, spermicides, cervical cap, contraceptive sponge, oral contraceptives or condoms. Abstinence is an alternative lifestyle and subjects practicing abstinence may be included in the study.

Exclusion Criteria:

  • Presence of any clinically significant illness, as detected by history, physical examination, and/or laboratory tests, that might influence driving performance (e.g., seizures, sleep apnea, narcolepsy, vertigo, chronic fatigue syndrome) or put the subject at increased risk of adverse events (e.g., cardiac arrhythmia, hypertension)
  • History of a clinically significant adverse event associated with cannabis or alcohol intoxication
  • Donation of more than 450 mL of blood within 14 days of study drug administration
  • If female, pregnant or nursing
  • Currently interested in or participating in drug abuse treatment, or participated in drug abuse treatment within 60 days preceding study enrollment
  • Currently taking drugs that are contraindicated for use with study drugs
  • Requires any special equipment to aid in driving (ex. pedal extensions, hand brake or throttle, spinner wheel knobs or other non-standard equipment)
  • Significant history of motion sickness or demonstrates significant simulator sickness during practice drives at screening (SSQ). Subjects must have scores below the following values on the SSQ: Nausea < 21, Oculomotor <32, Disorientation < 15, and Total Score < 32.
  • Current alcohol or cannabis use disorder, as identified by the Alcohol Use Disorders Identification Test for alcohol or Cannabis Use Disorders Identification Test for cannabis.
  • History of any illness that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the subject from study participation
  • Prior participation in a driver impairment or distraction-related research study conducted at NADS that uses the same base drive.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01620177

Locations
United States, Iowa
National Advanced Driving Simulator
Iowa City, Iowa, United States, 52242
Sponsors and Collaborators
University of Iowa
NHTSA
Investigators
Principal Investigator: Gary G Gaffney, M.D. National Advanced Driving Simulator
  More Information

No publications provided

Responsible Party: Gary R Gaffney, Associate Professor, College of Medicine, University of Iowa
ClinicalTrials.gov Identifier: NCT01620177     History of Changes
Other Study ID Numbers: 201109850
Study First Received: June 4, 2012
Last Updated: April 25, 2014
Health Authority: United States: Food and Drug Administration

Keywords provided by University of Iowa:
Cannabis
Marijuana
Marihuana
Alcohol
Driving

Additional relevant MeSH terms:
Alcohol Drinking
Marijuana Abuse
Drinking Behavior
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Ethanol
Anti-Infective Agents, Local
Anti-Infective Agents
Therapeutic Uses
Pharmacologic Actions
Central Nervous System Depressants
Physiological Effects of Drugs
Central Nervous System Agents

ClinicalTrials.gov processed this record on August 28, 2014