Clinical trial NCT03656029: Dose-response of Cannabis and Driving
Official title: Dose-dependent Effects of Smoked Cannabis on Simulated Driving Performance
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Driving Impaired
Cognitive Impairment
Abuse Cannabis
Lead sponsor: Centre for Addiction and Mental Health
Sponsor class: OTHER
First posted: 2018-09-04
Enrollment: 36
Sex: ALL
Minimum age (years): 19
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: This will be a within-subjects, counterbalanced, placebo-controlled study of placebo or 3 doses of cannabis
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Mean speed
timeFrame: Change in speed of driving between the time before smoking the cigarette and either 30 or 90 minutes after smoking the cigarette
Secondary outcomes:
measure: Standard deviation of lateral position
timeFrame: Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking
measure: reaction time
timeFrame: Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking
measure: Blood concentrations of THC and metabolites
timeFrame: 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
measure: Oral fluid concentrations of THC and metabolites
timeFrame: Change from levels before smoking to 4 time points after smoking: 30 minutes, 90 minutes, 2 hours and 6 hours
measure: Systolic and Diastolic Blood pressure
timeFrame: 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
measure: Heart rate
timeFrame: 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
measure: Respirations
timeFrame: 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
measure: Temperature
timeFrame: 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
measure: Visual Analog Scales
timeFrame: 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
measure: Verbal free recall test
timeFrame: Change from pre-smoking levels to those observed 60 minutes after smoking
measure: Useful field of view
timeFrame: Change from pre-smoking levels to those observed 60 minutes after smoking
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Center for Addiction and Mental Health
state: Ontario
Study officials:
affiliation: Centre for Addiction and Mental Health
name: Bruna Brands, PhD
role: PRINCIPAL_INVESTIGATOR
References: