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Completed

NCT Number: NCT03656029

Dose-response of Cannabis and Driving

Epidemiological studies have established a link between collisions while driving and cannabis use. With the changing legal landscape around cannabis, there is much interest in determining per se limits of cannabis while driving. The present study will evaluate driving on a driving simulator after smoking placebo or cannabis with 3 different levels of THC. THC is the active component in cannabis and blood, urine and oral fluid levels of THC will be correlated with driving impairment.

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Key information

Conditions

Driving Impaired Abuse Cannabis Chemically-Induced Disorders Cognition Disorders Cognitive Dysfunction Cognitive Impairment Marijuana Abuse Mental Disorders Neurocognitive Disorders Substance-Related Disorders

Age range

19 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Center for Addiction and Mental Health

Toronto, Ontario, M5S 2S1, Canada

About this study

Participants will attend the laboratory for 4 separate sessions, separated by about a week. In each session, participants will receive one of 3 doses of smoked cannabis or a placebo. Participants will not know which dose they are receiving. Participants will complete questionnaires, do cognitive tests and drive on a driving simulator before and after smoking the cannabis or placebo cigarette. Blood, urine and oral fluid will be collected throughout the 7-8 hour session to determine levels of THC and its metabolites. These values will be correlated with measures of driving impairment.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Near daily use of cannabis (1-5 days/week) confirmed by self-report and urine screening
  • Has held a class G2 or G licence (or equivalent from another jurisdiction) for at least 12 months
  • Willing to abstain from using cannabis for 72 hours prior to each practice or test session
  • Willing to abstain from alcohol for 48 hours prior to each session, and to abstain from all other drugs not medically required for the duration of the study (beginning 48 hours prior to the practice session)
  • Provides written and informed consent

Exclusion criteria

  • Diagnosis of severe medical or psychiatric condition
  • Meets criteria for current or lifetime alcohol or other substance use disorder, except tobacco use disorder and caffeine use disorder
  • Regular user of medication that may affect cognitive functioning and/or driver performance
  • Family history of schizophrenia or other psychotic disorder
  • Pregnant, looking to become pregnant, or breastfeeding

Treatment and study plan

Cannabis

Drug

Participants will smoke as much of the cigarette as they wish

Placebo

Drug

Participants will smoke a placebo cigarette

Primary outcomes

  1. Mean speed

    Time frame: Change in speed of driving between the time before smoking the cigarette and either 30 or 90 minutes after smoking the cigarette

    Speed of driving the simulator

Secondary outcomes

  1. Standard deviation of lateral position

    Time frame: Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking

    Driving measures

  2. reaction time

    Time frame: Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking

    Driving measures

  3. Blood concentrations of THC and metabolites

    Time frame: Change from before smoking cigarette to various time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Blood will be taken to determine how much THC entered the blood

  4. Oral fluid concentrations of THC and metabolites

    Time frame: Change from levels before smoking to 4 time points after smoking: 30 minutes, 90 minutes, 2 hours and 6 hours

    Participants will provide oral fluid to determine how much THC is in the oral fluid

  5. Systolic and Diastolic Blood pressure

    Time frame: Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Vital signs

  6. Heart rate

    Time frame: Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Vital signs

  7. Respirations

    Time frame: Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Vital signs

  8. Temperature

    Time frame: Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Vital signs

  9. Visual Analog Scales

    Time frame: Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours

    Tests designed to assess the degree of subjective effects of the drug. The questions will be scored on a scale from 0 to 100 and will consist of: 'I like this drug effect', 'this feels like cannabis', 'I feel this effect', 'I feel this high', 'I feel the good effects', 'I feel the bad effects', 'I feel the rush'

  10. Verbal free recall test

    Time frame: Change from pre-smoking levels to those observed 60 minutes after smoking

    Test of memory: Participants will be asked to recall words that are read from a list

  11. Useful field of view

    Time frame: Change from pre-smoking levels to those observed 60 minutes after smoking

    A computer test for visual processing speed, selective and divided attention

Sponsors and collaborators

Lead sponsor

Centre for Addiction and Mental Health

Other

Registry information

Official study title

Dose-dependent Effects of Smoked Cannabis on Simulated Driving Performance

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Sep 4, 2018
Registry last updated
Oct 7, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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