Evaluating the effects of oral cannabis and alcohol on impairment

The Impact of Oral Cannabis Administration and Co-Administration of Alcohol on Impairment

Phase 1 Interventional Johns Hopkins University · NCT04931095

This study is testing how different amounts of cannabis and alcohol affect people's ability to think and drive safely.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment90 (estimated)
Ages21 Years to 55 Years
SexAll
SponsorJohns Hopkins University Academic / other
Locations1 site (Baltimore, Maryland)
Trial IDNCT04931095 on ClinicalTrials.gov

What this trial studies

This clinical laboratory study aims to assess the individual and combined effects of oral cannabis and alcohol on impairment through a double-blind, placebo-controlled, within-subjects design. Participants will undergo seven outpatient sessions where they will self-administer varying doses of cannabis and alcohol, including a positive control condition. The study will measure performance on field sobriety tests, cognitive and psychomotor impairment, subjective drug effects, and simulated driving performance, alongside blood concentration analysis of THC and its metabolites.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 21 to 55 who have a history of binge drinking and cannabis use.

Not a fit: Patients who are pregnant, nursing, or have significant health issues or contraindications to alcohol or cannabis use may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide valuable insights into the safety and impairment effects of cannabis and alcohol co-use, informing public health guidelines and policies.

How similar studies have performed: Previous studies have explored the effects of cannabis and alcohol separately, but this specific combination and its interactive effects are less commonly studied, making this approach relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Have provided written informed consent
2. Be between the ages of 21 and 55
3. Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
4. Not be pregnant or nursing (if female). All females must have a negative serum pregnancy test at the screening visit and a negative urine pregnancy test at each study visit.
5. Have a body mass index (BMI) in the range of 19 to 36 kg/m2
6. Blood pressure at Screening Visit does not exceed a systolic blood pressure (SBP) of 150 mmHg or a diastolic blood pressure (DBP) of 90 mmHg
7. Have not donated blood in the prior 30 days.
8. Report at least 2 days of binge drinking in the past 90 days (greater than 4 or 5 drinks on a single occasion for women and men, respectively)
9. Report ≥ 1 use of cannabis in the past year
10. Provide negative urine test for illicit drug use (excluding THC) and negative breath alcohol test (0% BAC) at screening and before study sessions
11. Report at least 1 instance of simultaneous alcohol and use in the past year.

Exclusion Criteria:

1. Psychoactive drug use (aside from cannabis, nicotine, alcohol, or caffeine) in past month
2. Current use of over-the-counter (OTC) drugs, supplements/vitamins, or prescription medications that, in the opinion of the investigator or medical staff, will impact the participant's safety
3. History of or current evidence of significant medical condition
4. Evidence of current psychiatric condition \[(MINI for Diagnostic and Statistical Manual (DSM)-V)\]
5. Meet criteria for severe alcohol use disorder (MINI for DSM-V)
6. Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar) score \> 9
7. Been in treatment previously for alcohol or cannabis use disorder
8. Use of cannabis, on average, more than 2 times/week over past 3 months
9. Liver function tests more than 2x normal range
10. Enrollment in another clinical trial or receiving of any drug as part of research within past 30 days
11. Shipley vocabulary score \<18 (corresponds to 5th grade reading level).

Where this trial is running

Baltimore, Maryland

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cannabis IntoxicationAlcohol Intoxication
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.