Cannabis (THC) (Inhaled) Placebo
Cannabis vapor is produced from 500 mg of dried plant material (placebo) (0% THC). Participants will inhale ad libitum over 10 minutes.
Marihuana · MarijuanaLoading study record…
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Subjects will participate in a 4-visit study protocol in which they will be asked to complete a set of computerized tasks and a 45-minute simulated drive in a driving simulator. Subjects will be administered marijuana of varying pre-determined concentrations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) during 3 of the visits and alcohol during one of the visits. Throughout the duration of each visit, brain activity will be measured noninvasively using an electroencephalogram (EEG) headset. The purpose of this study is to: 1. Further understand the effects of acute cannabis intoxication on driving performance in a driving simulator 2. Develop and refine brain-based biomarkers of impairment due to acute cannabis intoxication
Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2021-07-12
What this record can show
This locally preserved record separates the registered protocol from source-reported registry results. Neither is a treatment recommendation.
Registry facts
At the University of Iowa, subjects who currently use cannabis recreationally (\> once a month but \< 5 times a week) will be recruited. They will then undergo a screening visit in which consent is obtained, questionnaires are given, and a physical exam is administered. They will then be scheduled for their next 3 (or 4 if participating in the alcohol arm), which will be at least one week apart. At each visit, in counter-balanced manner, subjects will be administered 500 mg of either placebo Marijuana (trace amounts of THC), high THC marijuana (7.5%), or very high THC marijuana (12.5%). All marijuana will be inhaled ad libitum via a Volcano® Digit vaporizer. Additionally, a subset of subjects will be asked to complete a fourth study visit that administers alcohol in place of cannabis. As subjects complete the third study visit and meet criteria for the alcohol arm, they will be invited to participate in the fourth study visit until eighteen subjects complete the study's alcohol arm. After drug administration, subjects will be asked to complete a set of computerized neurocognitive tasks (1 hour), followed by a simulated drive (45 minutes). Throughout the duration of each visit, EEG will be collected. EEG is a non-invasive method of recording the electrical activity of the brain. Additionally, blood draws will be taken at pre-determined time points. Finally, subjects will be monitored until the drug effects have subsided sufficiently to ensure it is safe to transport them home. Subjects will be transported home.
Linked local records
Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.
Interventions
Cannabis vapor is produced from 500 mg of dried plant material (placebo) (0% THC). Participants will inhale ad libitum over 10 minutes.
Marihuana · MarijuanaCannabis vapor is produced from 500 mg of dried plant material (7.5% THC). Participants will inhale ad libitum over 10 minutes.
Marihuana · MarijuanaCannabis vapor is produced from 500 mg of dried plant material (12.5% THC). Participants will inhale ad libitum over 10 minutes.
Marihuana · MarijuanaSubjects will be dosed to achieve a 0.05% Blood Alcohol Concentration (BAC), so the amount of alcohol consumed will be calculated to produce a peak BAC of 0.065%. Subjects will be served three equal-sized drinks, 10-minutes apart, and be instructed to pace each drink evenly over the 10-minute period.
Ethanol · Ethyl AlcoholEligibility
primary outcomes
Time frame: Through entire 45-minute drive, 0.5-1.3 hour post cannabis administration
Measured by standard deviation of lane position (SDLP, a gold standard metric of driving performance, O'Hanlon, 1984). This will provide a measure of general performance based on how well the driver maintains a consistent lane position. SDLP has been shown to be among the most important performance measures for evaluating the effects of psychophysiological changes due to impairment from medication use on driving performance (O'Hanlon, 1984).
Time frame: Between -0.7 hours and 8 hours post cannabis administration
Changes in electroencephalogram (EEG) spectral power measures for Delta, Theta, Alpha, Beta, Gamma bands. EEG is sampled at 256 Hertz (Hz) and power spectral measures are calculated in one-second time intervals.
Time frame: Between -0.7 hours and 8 hours post cannabis administration
Changes in heart rate as measured by electrocardiogram (ECG) (R-R interval). ECG is sampled at 256 Hz.
secondary outcomes
Time frame: -0.7 hour, 0.25 hour, 1.1 hour, 2 hour, 3 hour, 4.5 hour, 6 hour, 8 hour post cannabis administration
Measurement of THC concentration levels in plasma over the course of each visit compared to that of the other visits.
Time frame: -0.7 hour, 0.25 hour, 1.1 hour, 2 hour, 3 hour, 4.5 hour, 6 hour, 8 hour post cannabis administration
Measurement of THC concentration levels in whole blood over the course of each visit compared to that of the other visits.
Time frame: From 0.5 hours to 1.5 hours post cannabis administration
For each neurocognitive task, EEG will be recorded concurrently. There is a processing pipeline for measuring event-related potentials. This processing pipeline involves pre-processing, artifact removal, and averaging EEG evoked potentials in order to derive amplitude in microvolts.
Time frame: From 0.5 hours to 1.5 hours post cannabis administration
For each neurocognitive task, EEG will be recorded concurrently. There is a processing pipeline for measuring event-related potentials. This processing pipeline involves pre-processing, artifact removal, and averaging EEG evoked potentials in order to derive latency in milliseconds.
Publications
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