Pilot-Study for the Comparison of Biomarkers Between Regular Cannabis Users and Non-Users

Launched by UNIVERSITY OF BASEL · May 7, 2025

Keywords

ClinConnect Summary

This clinical trial is looking at how to better understand the effects of cannabis on driving. As more places legalize cannabis, it’s important to know how it affects people behind the wheel, but measuring THC (the active ingredient in cannabis) in the blood doesn’t give a clear picture of whether someone is impaired. This study aims to identify potential markers that can help determine how long ago a person last used cannabis. By doing this, researchers hope to find better ways to tell if someone is fit to drive or not, which is crucial for road safety.

To participate in this study, individuals must be between 18 and 65 years old, have a valid driver’s license, and use cannabis regularly (about once a week). They should not use cannabis or nicotine on the day of the study and must avoid alcohol for 24 hours before participating. People with certain medical conditions or who have taken specific medications recently will not be eligible. This study is still in the planning stages and is not recruiting participants yet, but it seeks to provide important insights that could help keep our roads safer for everyone.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Experience of smoking cannabis products, on average once a week. This may be in combination with tobacco.
• • Age 18-65 years Possession of driving license in at least one of the categories A, B, A1; B1, F, G or M
• • Sufficient knowledge of German
• • No cannabis inhalation or nicotine consumption on study day
• • No alcohol consumption within the last 24 h
• Exclusion Criteria:
• • Participation in a trial with investigational drugs within 30 days
• • Current or previous major psychiatric disorder (e.g., major depression, schizophrenia spectrum disorder)
• • Pregnancy or breastfeeding
• • Intake of CYP2C9, CYP2C19, and CYP3A4-inducers in the last 4 weeks before the study visit, e.g. rifampicin (antibiotic), carbamazepine (anticonvulsant), phenobarbital (anticonvulsant), phenytoin (anticonvulsant) or inhibitors, such as amiodarone (class III antiarrhythmic medication), antifungal drugs such as fluconazole, miconazole, voriconazole and itraconazole, antibiotics such as clarithromycin and sulfamethoxazole, ritonavir (protease inhibitor) and grapefruit juice.
• • The following conditions: vasopressin deficiency, pituitary tumor, active malignancy, severe hyponatremia requiring treatment, congestive heart failure, liver cirrhosis.