Clinical Study to Evaluate the Effects of Oral Delta-9-tetrahydrocannabinol (Δ9-THC) With and Without Alcohol on Perception and Driving Performance in Healthy Adults

Not Applicable

Not yet recruiting

• Conditions: Cannabis, Drug Effects; Driving Performance
• Interventions: Drug: Dronabinol (Marinol®); Drug: Dronabinol (Marinol®) + Alcohol; Drug: Alcohol beverage; Drug: Placebo

• Registration Number: NCT07176208
• Lead Sponsor: Food and Drug Administration (FDA)

Brief Summary

With the increasing prevalence and use of cannabis products by the public, there exists a need to better understand the safety impact of cannabis use, particularly when it comes to subjective perceptions of drug effect and driving impairment. This study aims to evaluate the dose-dependent effects of oral Δ9-THC alone and in combination with alcohol (0.08% BAC \[Blood Alcohol Concentration\]) on driving performance and subjective feeling in healthy adults. The results of this study will address current knowledge gaps on the effects of oral Δ9-THC on driving impairment across a clinically relevant dose range.

Detailed Description

The cannabis plant contains bioactive compounds known as cannabinoids, with delta-9 tetrahydrocannabidiol (Δ9-THC) and cannabidiol (CBD) being the most well-known cannabinoids in varieties of cannabis. With the increasing prevalence and use of cannabis products by the public, there exists a need to better understand the safety impact of cannabis use, particularly when it comes to subjective perceptions of drug effect and driving impairment. Studies have evaluated the effects of Δ9-THC on perception and driving capacity, however they have largely focused on inhaled routes of administration in experienced users and at relatively high doses. Research on the impact of oral Δ9-THC use in occasional users at lower doses (10 mg and below) on driving capacity is limited. Furthermore, despite the increasing prevalence of concurrent cannabis and alcohol use, there also remains a significant gap in research examining the combined effects of oral THC and alcohol on driving performance. This study aims to evaluate the dose-dependent effects of oral Δ9-THC alone and in combination with alcohol (0.08% BAC \[Blood Alcohol Concentration\]) on driving performance and subjective feeling in healthy adults. These effects will also be compared to the established alcohol-related impairment benchmark of blood alcohol content (0.08% BAC). The inclusion of an alcohol-only arm targeting 0.08% BAC will serve as a relevant positive control, representing the legal intoxication threshold in most states in the USA and providing a well-characterized impairment baseline against which THC and THC/alcohol combination effects can be measured. The results of this study will address current knowledge gaps on the effects of oral Δ9-THC on driving impairment across a clinically relevant dose range.

In this randomized, double-blind, 6-period crossover study, 48 healthy adult volunteers with driving experience and previous cannabis exposure will receive single oral doses across six treatment conditions: 5 mg THC, 10 mg THC, 5 mg THC combined with alcohol (target BAC of 0.08%), 10 mg THC combined with alcohol (target BAC of 0.08%), alcohol alone (target BAC of 0.08%), and matched placebo, with washout periods between treatments. The study will evaluate the dose-dependent effects of Δ9-THC (with and without alcohol) on both objective driving performance and subjective participant experience. Objectives primarily include standardized driving simulator assessments measuring standard deviation of lateral position (SDLP) and standard deviation of speed (SDSP), as well as subjective effects measured through use of Visual Analogue Scales (VAS). Assessments will be conducted at baseline and predetermined intervals post-dose over 24 hours.

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-08
• Study First Submitted QC: 2025-09-08
• Last Update Submitted: 2025-09-08
• Study First Posted: 2025-09-16
• Last Update Posted: 2025-09-16
• Study Start: 2025-09-22
• Primary Completion: 2026-02-27
• Study Completion: 2026-02-27

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 48

Inclusion Criteria

1. Subject signs an IRB approved written informed consent and privacy language as per national regulations (e.g., Health Insurance Portability and Accountability Act authorization) before any study related procedures are performed.
2. Subject is a healthy, non-smoking man or woman, 21 to 55 years of age, inclusive, who weighs at least 50 kg (110 lbs) and has a body mass index of 18.5 to 33.0 kg/m2, inclusive, at Screening and check-in (Day -1).
3. Subject possesses a valid U.S. driver's license and has driven a minimum of 600 miles per year for the previous 3 years.
4. During screening subjects will be assessed using a driving simulation test. Subject must not demonstrate any motion sickness as determined by the investigator and defined in the driving simulation operations manual and subject must not have erratic driving as defined in the Screening Visit Driving Practice Assessment Operational Manual.
5. Subject has normal medical history findings, clinical laboratory results, vital sign measurements, 12-lead ECG results, and physical examination findings at screening and check-ins or, if abnormal, the abnormality is not considered clinically significant (as determined and documented by the investigator or designee). Out of range tests may be repeated once for confirmation at screening and/or check-ins at investigator's discretion.
6. Subject is an occasional user of cannabis, defined as having at least one cannabis exposure within the last 6 months, but no daily use pattern and no cannabis exposure within the past month.
7. Subject has consumed alcohol equivalent to achieving approximately 0.10% BAC (approximately 3-4 standard drinks for females and 4-5 drinks for males over 1-2 hours) within the past year without experiencing significant adverse reactions. (Note: 1 standard drink = 12 ounces of beer [5% alcohol by volume], 5 ounces of wine [12% alcohol by volume], or 1.5 ounce of distilled spirits [40% alcohol]).
8. Subject must report at least 1 instance of simultaneous alcohol and cannabis use over the past one year without experiencing significant adverse reactions based on investigator discretion.
9. Participants must agree to refrain from using any of the following for the duration of the study: alcohol, nicotine containing products, marijuana (except for provided study drug) or marijuana-derived products, hemp or hemp-derived products, including CBD, and illicit drugs of any kind. Only THC and alcohol administered at the study site will be permitted.
10. Subject must test negative for severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) by a rapid antigen test at check-in. If a subject's test comes back as invalid, the test can be repeated.
11. Female subjects must be of non-childbearing potential (non-childbearing potential includes post-menopausal females defined as spontaneous amenorrhea for at least 12 months with FSH in the post-menopausal range or females who have undergone a surgical procedure that prevents pregnancy (e.g., hysterectomy, bilateral tubal ligation, occlusion, or salpingo-oophorectomy) or, if they are of childbearing potential, they must have negative serum HCG at screening and check-in and be practicing 2 effective methods of birth control (as determined by the investigator or designee; only one of the methods, but not both, may be a barrier technique) from Screening until at least 3 months after the end of the study. They must agree not to donate eggs for 30 days until after study completion.
12. Male subjects must agree to practice 2 effective methods of birth control (as determined by the investigator or designee) beginning at check-in (Day -1) until at least 3 months after the last dose of study drug. Subject must also agree to inform female partner(s) about participation in the study and ensure they are using a highly effective form of contraception (e.g., hormonal birth control or copper IUD). Male subjects may not donate sperm for 90 days after the end of the study.
13. Subject agrees to and is highly likely (as determined by the investigator) to comply with the protocol defined procedures and to complete the study.

Exclusion Criteria

1. A history of cannabis use disorder or use of any psychoactive drug in the last month.
2. Any reported history of alcohol intolerance.
3. Alcohol intolerance as detected by ethanol patch testing.
4. Subject has a dry mouth or history of salivary gland disfunction or surgery.
5. A history of any psychiatric diagnosis, including mood, anxiety, and psychotic disorders.
6. Any family history of schizophrenia or other psychotic illness.
7. Any history of seizures, epilepsy, or traumatic brain injury.
8. History of syncope within 3 months prior to screening or any history of recurrent and/or unexplained episodes of syncope.
9. A positive test result for alcohol and drugs of abuse (amphetamines, barbiturates, benzodiazepines, cocaine, alcohol, opiates, phencyclidine, propoxyphene, methadone, ) at screening and check-in (Day -1).
10. Use or intend to use any medications other than birth control, including prescription, OTC, herbal or recreational products (excluding cannabis) in the 14 days prior to check-in (Day -1), unless deemed acceptable by the investigator.
11. Currently participating in another clinical study of an investigational drug or has been treated with any investigational drug within 30 days or 5 half-lives (whichever is longer) of dosing for this study.
12. Subject has used nicotine-containing products (e.g., cigarettes, cigars, chewing tobacco, snuff, electronic cigarettes) within 6 weeks of Screening. Subjects must refrain from using these throughout the study.
13. Subject is unable to tolerate a controlled, quiet study conduct environment, including avoidance of music, television, movies, games, and activities that may cause excitement, emotional tension, or arousal during the prespecified time points.
14. Subject has known or suspected allergies or sensitivities to the study drug, delta 9-THC or sesame seeds/oil.
15. Subject has a history of consuming more than 14 units of alcoholic beverages per week within 6 months before Screening, has a history of alcohol use disorder or drug/chemical/substance abuse within 2 years before Screening (Note: 1 unit = 12 ounces of beer, 5 ounces of wine, or 1.5 ounce of spirits/hard liquor).
16. Subject tests positive for potential active alcohol use disorder (as determined by a score of 3 or greater on the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C).
17. Subject has a history of suicidal ideation or previous suicide attempts.
18. Subject has a history or evidence of a clinically significant disorder, condition, or disease (e.g., cancer, human immunodeficiency virus [HIV], hepatic or renal impairment) that, in the opinion of the investigator, would pose a risk to subject safety or interfere with the study evaluation, procedures, or completion.
19. Subject has a diagnosis of COVID-19 or any signs or symptoms that are consistent with COVID-19 per CDC recommendations at screening or check-in (Day -1). These include subjects with fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, diarrhea, or other symptoms indicative of likely COVID-19 in the opinion of the investigator.
20. Subject has any condition possibly affecting study drug absorption (e.g., gastrectomy, Crohn's disease, irritable bowel syndrome).
21. Subject has clinical laboratory test results (hematology, serum chemistry and urinalysis) at screening or check-ins that are outside the reference ranges provided by the clinical laboratory and considered clinically significant by the investigator. Out of range tests may be repeated once for confirmation at screening and/or check-ins at investigator's discretion.
22. Subject has a mean systolic blood pressure <90 or >140 mmHg or a mean diastolic blood pressure <50 or >90 mmHg at either screening or check-ins, unless determined not clinically significant per investigator. Blood pressure will be measured after the subject has been resting in a sitting position for approximately 5 minutes. Two blood pressure repeats will be permitted in instances where initial measures out of normal range.
23. Subject has a positive test result at screening for HIV 1 or 2 antibody, hepatitis C virus antibodies, or hepatitis B surface antigen.
24. Subject is unable or unwilling to undergo multiple venipunctures for blood sample collection because of poor tolerability or is unlikely to complete the study due to poor venous access.
25. Subject has had any significant blood loss, donated 1 unit (450 mL) of blood or more, or received a transfusion of any blood or blood products within 60 days, or donated plasma within 7 days before check-in.
26. Subject with any visual or hearing impairment that will prevent accurate completion of study assessments (as determined by the investigator).
27. Subject has any other condition that precludes his or her participation in the study (as determined by the investigator).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Treatment A - 5 mg Δ9-THC + Placebo beverage	Dronabinol (Marinol®)	Subjects in this arm will receive one 5 mg oral dose of THC and a placebo beverage
Treatment B - 10 mg Δ9-THC + Placebo beverage	Dronabinol (Marinol®)	Subjects in this arm will receive one 10 mg oral dose of THC and a placebo beverage
Treatment C - 5 mg Δ9-THC + Alcohol beverage with BAC target of 0.08%	Dronabinol (Marinol®) + Alcohol	Subjects in this arm will receive one 5 mg oral dose of THC and an alcohol beverage targeting a blood alcohol concentration (BAC) of 0.08%
Treatment D - 10 mg Δ9-THC + Alcohol beverage with BAC target of 0.08%	Dronabinol (Marinol®) + Alcohol	Subjects in this arm will receive one 10 mg oral dose of THC and an alcohol beverage targeting a blood alcohol concentration (BAC) of 0.08%
Treatment E - Placebo capsule + Alcohol beverage with BAC target of 0.08%	Alcohol beverage	Subjects in this arm will receive one placebo capsule and an alcohol beverage targeting a blood alcohol concentration (BAC) of 0.08% as a positive control
Treatment F - Placebo capsule + Placebo beverage	Placebo	Subjects in this arm will receive one placebo capsule and a placebo beverage

Primary Outcome Measures

Name	Time	Method
Simulated driving performance as measured by Standard Deviation of Lateral Position (SDLP) after Δ9-THC administration alone or in combination with alcohol compared to alcohol alone.	Up to 8 hours after study drug administration.	Simulated driving performance will be measured by the endpoint standard deviation of lateral position (SDLP) using a STISIM (model M4000-R) driving simulator after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to active control (alcohol alone).

Secondary Outcome Measures

Name	Time	Method
Simulated driving performance as measured by Standard Deviation of Lateral Position (SDLP) after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 8 hours after study drug administration.	Simulated driving performance will be measured by the endpoint standard deviation of lateral position (SDLP) using a STISIM (model M4000-R) driving simulator after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo.
Simulated driving performance as measured by Standard Deviation of Speed Position (SDSP) after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 8 hours after study drug administration.	Simulated driving performance will be measured by the endpoint standard deviation of speed position (SDSP) using a STISIM (model M4000-R) driving simulator after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo.
Simulated driving performance as measured by Standard Deviation of Speed Position (SDSP) after Δ9-THC administration alone or in combination with alcohol compared to alcohol alone.	Up to 8 hours after study drug administration.	Simulated driving performance will be measured by the endpoint standard deviation of speed position (SDSP) using a STISIM (model M4000-R) driving simulator after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to alcohol alone.
Maximum subjective self-rated driving impairment after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective self-rated driving impairment after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS "drug driving impairment"): "How much did the study drug affect your driving?"
Maximum subjective feeling state of VAS "Drug Effect" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Drug Effect" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS "Drug Effect"): "Are you feeling a drug effect right now?"
Maximum subjective feeling state of VAS "Willingness to Drive" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Willingness to Drive" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS "Willingness to Drive"): "Would you drive in your current state right now?"
Maximum subjective feeling state of VAS "Confidence in Driving" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Confidence in Driving" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS Confidence in Driving): "How confident are you in your driving ability?"
Maximum subjective feeling state of VAS "Liking" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Liking" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS Liking): "How much do you like the drug effects right now?"
Maximum subjective feeling state of VAS "High" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "High" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS High): "How high do you feel right now?"
Maximum subjective feeling state of VAS "Bad Effects" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Bad Effects" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS Bad Effects): "Are you feeling any bad effects right now?"
Maximum subjective feeling state of VAS "Drowsy" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Drowsy" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS Drowsy): "How drowsy do you feel right now?"
Maximum subjective feeling state of VAS "Take Drug Again" after Δ9-THC administration alone or in combination with alcohol compared to placebo.	Up to 24 hours after study drug administration.	Maximum subjective feeling state of VAS "Take Drug Again" after Δ9-THC administration (5 mg, 10 mg, 5 mg with alcohol, 10 mg with alcohol) compared to placebo will be measured by the VAS question (VAS Take Drug Again): "How likely are you to take this drug again?"

Trial Locations

Locations (1)

Spaulding Clinical Research; 🇺🇸 West Bend, Wisconsin, United States