ClinicalTrials.gg
CompletedNCT04970342PDIDUpdated Jul 25, 2023Results posted

Validation of the Drug Impaired Driving Scenario (DIDS) on the CRCDS-miniSim

A Phase 1 interventional study of Placebo (Lactose) Capsule and 0.75 mg Alprazolam Capsule in Driving Behavior and Driving Under the Influence, sponsored by Timothy L. Brown. Completed at 1 site in United States. Open to participants aged 19 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-07-25.

Primary conditionDriving Under the Influence(the registry's first term)UnverifiedIs this wrong?Driving Under the Influence is a broad heading, used only when no more specific condition is named. No better condition is named, so the registry's term is kept.

Sponsored by Timothy L. Brown · Phase 1, Interventional, and Basic science

Phase
Phase 1
Study type
Interventional
Enrollment
13
Allocation
Randomized
Ages
19 Years to 45 Years
Sex
All
01

Study summary

Subjects will participate in a 4-visit study protocol at the National Advanced Driving Simulator, part of the University of Iowa, in which they will be asked to complete assorted questionnaires, computerized cognitive tasks, and a simulator drive. Subjects will be administered 0.75 mg alprazolam (Xanax) or placebo and 500 mg vaporized cannabis (6.18% THC / \<0.025% CBD) or placebo (0% THC / 0% CBD).

The primary objective of this study is to validate the Drug Impaired Driving Scenario (DIDS) using the CRCDS-2 driving simulator by assessing the acute effects of cannabis relative to placebo on simulated driving performance. Assay sensitivity will be demonstrated by the significant effect of 0.75 mg alprazolam (active comparator) on driving and cognitive endpoints.

Read the detailed description

At the University of Iowa's National Advanced Driving Simulator (NADS), normal healthy subjects who currently use cannabis recreationally (at least once a month) will be recruited. The study involves four visits, the first of which is a screening visit of approximately 3 hours. At the screening visit, consent is obtained, questionnaires are given, and a physical and psychological exam is administered. Subjects will also train on study procedures, such as the cognitive testing, the simulator drive, and the cannabis inhalation procedure. Subjects will then be scheduled for their three treatment visits, which will be one week apart..

The treatment visits will have a clean (double placebo) and two treatment visits (active alprazolam and placebo cannabis, placebo alprazolam and active cannabis). The alprazolam dose is 0.75 mg and the cannabis dose is 500 mg. All cannabis will be inhaled via a Volcano® Digit vaporizer using the Foltin Puff Procedure. Each of the treatment visits will last approximately twenty-three hours and will include intake with eligibility and baseline testing, transport to a local hotel, an overnight stay at the hotel, transport to NADS, being dosed with study drugs or placebos, cognitive assessments, a simulator drive, and assorted questionnaires. There will also be 8 mL blood sampling before dosing, before driving, and after driving. Each randomized subject will complete a treatment visit of each type one week apart in a counterbalanced sequence.

Meals will be provided at the treatment visits (dinner, snack, breakfast, lunch). Subjects will be monitored until the drug effects have subsided sufficiently to ensure it is safe to transport them home. Subjects will need to arrange their own transportation; they will not be permitted to drive themselves home after the treatment visits.

02

Conditions studied

  • Driving Behavior
  • Driving Under the Influence

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Keywords

  • Driving
  • Cannabis
  • Xanax
  • Marijuana
  • Alprazolam
  • Driving Impairment
  • Substance Use
  • SDLP
  • CogScreen
  • CRCDS
03

In context

Driving Under the Influence Unverified

39 studies on the registry are indexed under Driving Under the Influence; 5 are open to participants now.

This study's enrollment of 13 is below the median of 60 across 29 interventional studies indexed under Driving Under the Influence.

Browse Driving Under the Influence studies →

Lead sponsor

Timothy L. Brown is the lead sponsor of 2 studies on the registry; none are open to participants now.

Compared within Driving Under the Influence, the registry's first condition term, which may not be this study's main condition. Counted across the registry records on this site, refreshed daily. How we classify →

04

Who can participate

Ages eligible
19 Years to 45 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Understands and provides written prior to the initiation of any protocol-specific procedures.
  • Able to comprehend and willing to comply with the requirements of the protocol.
  • Healthy male or female adult, 19 to 45 years of age, inclusive, at Screening.
  • Regular sleep pattern (usual bedtime between 21:00 and 00:00).
  • Score \<10 on Epworth Sleepiness Scale at Screening.
  • Able to reliably perform study assessments at Screening (On practice scenario, SDLP no higher than 1 standard deviation greater than the mean for normal healthy adults completing the practice scenario and subject has 7 or more correct hits on the Divided Attention task; CogScreen SDC Correct no less than 1 standard deviation below the mean for healthy adults); demonstrates the ability to understand task instructions at Screening; and is physically (e.g., adequate manual dexterity, vision, and hearing) and cognitively capable of performing study tasks at Screening.
  • Possesses (and is willing to provide) a valid driver's license and is an active driver.
  • Determined to be (by self-report) an active cannabis user with use of at least once per month over the preceding 90 days.
  • Willing to abstain from cannabis use (other than study drug) beginning at the end of Screening until discharge from NADS on Day 2 of Treatment Period 3.
  • Female subjects must meet one of the following criteria: 1) If of , female subjects agree to use two regimens or remain abstinent during the study; or 2) if of non-childbearing potential, female subjects should be surgically sterile or in a menopausal state.

Exclusion criteria

Exclusion Criteria:

  • A significant history and/or presence of hepatic, renal, cardiovascular, pulmonary, neurological, psychiatric, gastrointestinal, hematological, immunologic, ophthalmologic, metabolic, or oncological disease, or any other medical issue that would, in the opinion of the Investigator, present undue risk for the subject in the study.
  • A history of suicidal behavior within 24 months of Screening, has answered YES to questions 3, 4, or 5 on the C-SSRS at Screening or at any clinic admission, or is currently at risk of suicide in the opinion of an Investigator.
  • A recent history (within 6 months prior to Screening) of substance use disorder (including alcohol) (as judged by the Investigator) or regularly consumes >2 alcoholic drinks/day during the last 3 months prior to Screening (1 alcoholic drink is approximately equivalent to: beer [284 mL], wine [125 mL/4 ounces], or distilled spirits [25 mL/1 ounce]). Subjects who consume 3 drinks per day but less than 14 drinks per week may be enrolled at the discretion of the Investigator.
  • Demonstrates simulator sickness questionnaire scores which are indicative of simulator sickness as defined in the driving simulation operations manual.
  • Regularly consumes excessive amounts of caffeine, defined as greater than 6 servings of coffee, tea, cola, or other caffeinated beverages per day.
  • Smokes more than 10 cigarettes or e-cigarettes, or 3 cigars or pipes per day, or is unable to refrain from smoking during study visits.
  • Has been exposed to an drug or device within the 30 days, or 5 half lives (if known), whichever is longer, prior to Screening.
  • Has used a prescription or over-the-counter medication known to cause sedation within 7 days prior to Admission for Period 1 and is unwilling or unable to refrain from sedating medication use during study participation.
  • Has used any benzodiazepine, barbiturate, or GABAA modulator (e.g., eszopiclone, zopiclone, zaleplon, and zolpidem) within 28 days prior to Admission for Period 1 or is unwilling or unable to refrain from medication use during study participation.
  • Has a history of surface antigen, antibodies, or (HIV) antibodies 1 or 2.
  • Is pregnant or breastfeeding at Screening or any clinic admission or will attempt to become pregnant at any time during study participation.
  • Has a abnormal finding on 6-lead (ECG) at Screening or at any clinic admission. The ECG may be repeated once for confirmatory purposes if initial values obtained exceed the limits specified.
  • Has a positive urine test for drugs of abuse (other than tetrahydrocannabinol (THC)) or Breath Alcohol Concentration (BrAC) > 0.0 at Screening or any admission.
  • Has any clinically significant abnormal physical examination finding at Screening or any clinic admission.
  • Participates in night shift work.
  • Has traveled across ≥1 time zone in the 2 weeks prior to Admission for Period 1 or is expected to travel across ≥1 time zone during the study.
  • Is investigative site personnel or their immediate families (spouse, parent, child, or sibling whether biological or legally adopted).
Terms in these criteria, in plain language(9)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

05

Study design

Phase
Phase 1
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
13 participants (actual)

Study arms

  • Experimental
    "Sober" or Double Placebo

    Subject receives alprazolam capsule containing placebo (lactose). Subject receives placebo cannabis (0% THC / 0% CBD).

    Drug: Placebo (Lactose) Capsule · Drug: Cannabis (0%/ THC / 0% CBD)

  • Experimental
    Active Alprazolam (Xanax), Placebo Cannabis

    Subject receives active 0.75 mg alprazolam capsule. Subject receives placebo cannabis (0% THC / 0% CBD).

    Drug: 0.75 mg Alprazolam Capsule · Drug: Cannabis (0%/ THC / 0% CBD)

  • Experimental
    Placebo Alprazolam (Xanax), Active Cannabis

    Subject receives alprazolam capsule containing placebo (lactose). Subject receives active cannabis (6.18% THC / \<0.025% CBD).

    Drug: Placebo (Lactose) Capsule · Drug: Cannabis (6.18% THC / <0.025% CBD)

Interventions

  • DrugPlacebo (Lactose) Capsule

    Single dose on two of the three study visits, orally administered 40 minutes prior to cannabis dose

    Also known as: Placebo, Placebo Alprazolam

  • Single dose on one of the three study visits, orally administered 40 minutes prior to cannabis dose

    Also known as: Xanax, Active Alprazolam, Active Xanax

  • DrugCannabis (6.18% THC / <0.025% CBD)

    Drug page: Cannabis sativa subsp. indica TOP

    Cannabis vapor is produced from 500 mg of dried plant material (6.18% THC / \<0.025% CBD). Subjects will inhale using the Foltin Puff Procedure over 10 minutes. Single inflated bag/dose consumed via inhalation 40 minutes after alprazolam dose on one of the three study visits.

    Also known as: Marijuana, Marihuana, Active Cannabis

  • DrugCannabis (0%/ THC / 0% CBD)

    Drug page: Cannabis sativa subsp. indica TOP

    Cannabis vapor is produced from 500 mg of dried plant material (0% THC / 0% CBD). Subjects will inhale using the Foltin Puff Procedure over 10 minutes. Single inflated bag/dose consumed via inhalation 40 minutes after alprazolam dose at two of the three study visits.

    Also known as: Marijuana, Marihuana, Placebo Cannabis, Placebo

06

What researchers measure

Primary outcomes

  1. Standard Deviation of Lateral Position (SDLP)

    The ability to keep the vehicle straight in the lane. Data is presented from the a rural drive with a concurrent divided attention task.

    Time frame: over one hour during the course of the simulator drive conducted 45 minutes post-dose at Treatment Visit 1, 2, and 3

Secondary outcomes

  1. Lane Exceedences

    Count of the number of times the simulated vehicle leaves the driving lane, will be compared across treatments. Data is from a rural drive with a concurrent divided attention task.

    Time frame: over one hour during the course of the simulator drive conducted 45 minutes post-dose at Treatment Visit 1, 2, and 3

07

Results

Posted Jul 25, 2023

Participant flow

Treatment Visit 1 (1 Day)
Participant flow — Treatment Visit 1 (1 Day)
MilestoneSequence 1Sequence 2Sequence 3Sequence 4Sequence 5Sequence 6
Started221111
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Washout (7 Days)
Participant flow — Washout (7 Days)
MilestoneSequence 1Sequence 2Sequence 3Sequence 4Sequence 5Sequence 6
Started221111
Completed221111
Not completed000000
Treatment Visit 2 (1 Day)
Participant flow — Treatment Visit 2 (1 Day)
MilestoneSequence 1Sequence 2Sequence 3Sequence 4Sequence 5Sequence 6
Started221111
Completed221111
Not completed000000
Washout (7 Days)
Participant flow — Washout (7 Days)
MilestoneSequence 1Sequence 2Sequence 3Sequence 4Sequence 5Sequence 6
Started221111
Completed221111
Not completed000000
Treatment Visit 3 (1 Day)
Participant flow — Treatment Visit 3 (1 Day)
MilestoneSequence 1Sequence 2Sequence 3Sequence 4Sequence 5Sequence 6
Started221111
Completed221111
Not completed000000

Outcome measures

PrimaryStandard Deviation of Lateral Position (SDLP)

The ability to keep the vehicle straight in the lane. Data is presented from the a rural drive with a concurrent divided attention task.

Time frame:
over one hour during the course of the simulator drive conducted 45 minutes post-dose at Treatment Visit 1, 2, and 3
Reported as:
Mean · cm
Standard Deviation of Lateral Position (SDLP)
cm"Sober" or Double PlaceboActive Alprazolam (Xanax), Placebo CannabisPlacebo Alprazolam (Xanax), Active Cannabis
Standard Deviation of Lateral Position (SDLP)25.490 ± 5.73737.849 ± 6.43433.086 ± 12.375
SecondaryLane Exceedences

Count of the number of times the simulated vehicle leaves the driving lane, will be compared across treatments. Data is from a rural drive with a concurrent divided attention task.

Time frame:
over one hour during the course of the simulator drive conducted 45 minutes post-dose at Treatment Visit 1, 2, and 3
Reported as:
Mean · number of times vehicle departed lane
Lane Exceedences
number of times vehicle departed lane"Sober" or Double PlaceboActive Alprazolam (Xanax), Placebo CannabisPlacebo Alprazolam (Xanax), Active Cannabis
Lane Exceedences5.750 ± 6.25136.500 ± 19.41329.875 ± 48.147

Adverse events

Collected over Duration of study participation. Adverse Events were captured from the time of enrollment to the time of study follow-up, a maximum duration of 5 weeks.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
"Sober" or Double Placebo0/8 (0%)0/8 (0%)1/8 (12.5%)
Active Alprazolam (Xanax), Placebo Cannabis0/8 (0%)0/8 (0%)0/8 (0%)
Placebo Alprazolam (Xanax), Active Cannabis0/8 (0%)0/8 (0%)0/8 (0%)
Most frequent other events
Most frequent other events
Event"Sober" or Double PlaceboActive Alprazolam (Xanax), Placebo CannabisPlacebo Alprazolam (Xanax), Active Cannabis
NauseaGastrointestinal disorders1/80/80/8

Baseline characteristics

All subjects randomized completed all study arms/treatments, but in a different randomization sequence. Data was not used from subjects enrolled but not randomized.

Age, Categorical
Age, Categorical(Participants)Randomized Subjects
<=18 years0
Between 18 and 65 years8
>=65 years0
Sex: Female, Male
Sex: Female, Male(Participants)Randomized Subjects
Female3
Male5
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Randomized Subjects
Hispanic or Latino3
Not Hispanic or Latino5
Unknown or Not Reported0
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Randomized Subjects
American Indian or Alaska Native0
Asian0
Native Hawaiian or Other Pacific Islander0
Black or African American0
White7
More than one race0
Unknown or Not Reported1
Region of Enrollment
Region of Enrollment(participants)Randomized Subjects
United States8
08

Study locations

1 site
  • National Advanced Driving Simulator
    Iowa City, Iowa 52242, United States
09

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No — Data is being collected to support regulatory efforts by the government and data will not be available to those outside of the research team and government at this time.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 25, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT04970342
Lead sponsor
Timothy L. Brown
Collaborators
National Highway Traffic Safety Administration (NHTSA), Acclaro Research Solutions, Inc., Cognitive Research Corporation
Responsible party
Timothy L. Brown (Director of Drugged Driving Research, University of Iowa) — Sponsor-investigator
First posted
Jul 21, 2021
Start date
Jul 16, 2021
Primary completion
Aug 21, 2021
Completion
Aug 21, 2021
Results posted
Jul 25, 2023
Last update
Jul 25, 2023

Study contacts

Timothy L Brown
principal investigator · National Advanced Driving Simulator, University of Iowa

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Aug 2022. You cannot join it, but the record below documents what was studied.

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Discussion

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Studies of the drugs tested here: Alprazolam · Cannabis sativa subsp. indica TOP

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