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Effects of Inhaled Cannabis on Driving Performance

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT01620177
Recruitment Status : Completed
First Posted : June 15, 2012
Results First Posted : June 1, 2017
Last Update Posted : May 2, 2018
Sponsor:
Collaborators:
National Highway Traffic Safety Administration (NHTSA)
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
Gary R Gaffney, University of Iowa

Tracking Information
First Submitted Date  ICMJE June 4, 2012
First Posted Date  ICMJE June 15, 2012
Results First Submitted Date  ICMJE April 17, 2017
Results First Posted Date  ICMJE June 1, 2017
Last Update Posted Date May 2, 2018
Study Start Date  ICMJE July 2012
Actual Primary Completion Date March 2014   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: May 31, 2017)
Driving Performance [ Time Frame: Through entire drive, 0.5-1.3 hr post cannabis administration. ]
Measured by standard deviation of lane position. Metrics of driving performance were modeled using the SAS GLM Select function to identify changes in driver performance. Numbers represents coefficients on the regression equation such that this increase would be expected for every unit increase. A unit for THC is 1 ng/ml and a unit for BAC is 0.01% BAC. In understanding the regression coefficients, for THC the units for the coefficient would be expressed as cm per (ng/ml of THC), and for BrAC the units for the coefficient would be expressed as cm per (0.01% BrAC). The overall regression equation would be represented as SDLP = Intercept + Cthc x THC + Cbrac x BrAC. The coefficients indicate the strength of the effect on driving performance with higher coefficients indicating larger effects relative to the concentrations. Coefficients of zero indicate no effect or interactive effect.
Original Primary Outcome Measures  ICMJE
 (submitted: June 14, 2012)
Driving Performance [ Time Frame: Through entire drive, 0.5-1.1 hr post cannabis administration. ]
Measured by speed, lane position, steering wheel position, reaction time, headway to lead vehicle, eye tracking
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: May 31, 2017)
  • 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 ]
    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 ]
    Measurement of THC concentration levels in whole blood over the course of each visit compared to that of the other visits.
Original Secondary Outcome Measures  ICMJE
 (submitted: June 14, 2012)
  • Rogers gambling task [ Time Frame: -1.2 hr, 1.5 hr, 3 hr, 5.5, 7.5 hr post cannabis administration ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    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 ]
    Measurement of THC concentration levels in saliva over the course of each visit compared to that of the other visits.
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Effects of Inhaled Cannabis on Driving Performance
Official Title  ICMJE Effects of Inhaled Cannabis on Driving Performance
Brief Summary

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.

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.
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Condition  ICMJE
  • Alcohol Drinking
  • Cannabis
Intervention  ICMJE
  • 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:
    • Ethanol
    • 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
Study Arms  ICMJE
  • Experimental: 0% THC with 0.065 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
  • Experimental: 2.5-3.5% THC with 0.065 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
  • Experimental: 6.0-7.5% THC and 0.065 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
  • Experimental: 2.5-3.5% THC with 0 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
  • Experimental: 6.0-7.5% THC with 0 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
  • Experimental: 0% THC with 0 g/dL BAC
    Interventions:
    • Drug: Alcohol(oral) and placebo
    • Drug: Cannabis(THC)(Inhaled) and Placebo
Publications *

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: May 31, 2017)
98
Original Estimated Enrollment  ICMJE
 (submitted: June 14, 2012)
60
Actual Study Completion Date  ICMJE March 2014
Actual Primary Completion Date March 2014   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

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.
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 21 Years to 55 Years   (Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT01620177
Other Study ID Numbers  ICMJE 201109850
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Gary R Gaffney, University of Iowa
Study Sponsor  ICMJE Gary R Gaffney
Collaborators  ICMJE
  • National Highway Traffic Safety Administration (NHTSA)
  • National Institute on Drug Abuse (NIDA)
Investigators  ICMJE
Principal Investigator: Gary G Gaffney, M.D. National Advanced Driving Simulator
PRS Account University of Iowa
Verification Date April 2018

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP