Overview
The relevance of driving under the influence of cannabis is becoming increasingly important in the context of legalization. However, the measurement of tetrahydrocannabinol (THC) blood concentration is an inadequate marker for assessing driving impairment. Currently, there is no reliable marker available for estimating the time of last cannabis inhalation, which would provide a promising tool for regulating driving under the influence of cannabis. This pilot study aims to explore potential biomarkers and factors that could approximate the timing of the last cannabis inhalation, with emphasis on the potential explanation of interindividual differences in THC pharmacokinetics and -dynamics. The results will assist future research aimed at improving the ability to distinguish between impaired and unimpaired cannabis users in road traffic. These findings are of significant importance for road safety and for society at large, as they may provide more objective markers for cannabis inhalation, thereby permitting a methodologically sound evaluation of driving under the influence of cannabis.
Eligibility
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.