Overview
This human laboratory study will use cognitive, behavioral, and subjective measures to characterize impairment associated with co-use of alcohol and vaporized cannabis. Participants (n=32) will complete 7 double-blind, double-dummy outpatient sessions in randomized order. In each session, participants will self-administer placebo (0 mg THC) or active vaporized cannabis (5 or 25 mg THC, via a handheld vaporizer called the Mighty Medic) and a placebo drink (BAC 0.0%) or alcohol drink calculated to produce a breath alcohol concentration (BAC) of 0.05%. Participants will also complete a positive control session in which the participant administers placebo cannabis and alcohol at a target BAC of 0.08% (the legal threshold for driving impairment in most U.S. states).
Description
This study will be conducted at the Johns Hopkins Behavioral Pharmacology Research Unit (BPRU). Participants will complete a screening visit, and, if eligible, will then complete 7 experimental drug administration sessions in randomized order where the participant will vaporize cannabis-containing capsules (or "pods") (containing 0, 5, or 25mg THC) with a drink that contains no alcohol or alcohol (alcohol-containing drinks will be calculated to produce a breath alcohol concentration, BAC, of 0.05%). There is also a positive control session where participants will vaporize placebo cannabis with an alcohol drink calculated to produce a BAC of 0.08%. Each session will last approximately 8 hours and will be separated by at least 48 hours to allow for sufficient drug washout. Participants may complete up to 2 sessions per week. Drugs will be administered in a double-blind and double-dummy fashion (i.e., participants will always receive both active or placebo cannabis and active or placebo alcohol). During each session, a battery of assessments including blood collection, subjective questionnaire administration, cognitive performance testing, and simulated driving will be conducted.
Eligibility
Inclusion Criteria:
- Have provided written informed consent
- Be at least 21 years of age
- Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
- 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
- Have not donated blood in the prior 30 days
- Report at least 1 day of binge drinking in the past 3 months (greater than 4 or 5 drinks on a single occasion for women and men, respectively)
- Report at least 1 use of cannabis in the past 3 years
- Provide negative urine test for illicit drug use (excluding THC) and negative breath alcohol test (0% BAC) at screening and before study sessions
- Report at least 1 lifetime instance of simultaneous alcohol and cannabis use
- Current concomitant prescription medication use that may interact with the investigational study drug, including inhibitors and inducers of CYP2CP and CYP3A4 as well as highly-protein bound drugs and drugs with a narrow therapeutic index such as warfarin, cyclosporine, and amphotericin B
Exclusion Criteria:
- Psychoactive drug use (aside from cannabis, nicotine, alcohol, or caffeine) in the past month
- History of or current evidence of significant medical condition that would put the participant at risk
- Evidence of current psychiatric condition (MINI for DSM-V)
- Meet criteria for severe alcohol use disorder (MINI for DSM-V)
- CIWA-Ar score > 9
- Use of cannabis, on average, more than 3 days/week over past 3 months
- Enrollment in another clinical trial or receiving of any drug as part of research within past 30 days
- Shipley vocabulary score <18 (corresponds to 5th grade reading level)