Assessment of Driving Capability Through the Use of Clinical and Psychomotor Tests in Relation to Blood Cannabinoids Levels Following Oral Administration of 20 mg Dronabinol or of a Cannabis Decoction Made with 20 or 60 mg Δ9-THC*
Annick Ménétrey, Marc Augsburger, Bernard Favrat, Marie A. Pin, Laura E. Rothuizen, Monique Appenzeller, Thierry Buclin, Patrice Mangin, Christian Giroud
Journal of Analytical Toxicology July 1, 2005 DOI: 10.1093/jat/29.5.327 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized crossover trial Double-blind Peer reviewed |
|---|---|
| Population | Participants in a controlled clinical study (number not stated) |
| Interventions | THC Dronabinol |
| Dose | 16.5 mg THC, 45.7 mg THC, 20 mg dronabinol |
| Topics | Cannabis |
| Citations | 89 |
| Key findings | Oral THC and dronabinol impair driving-related skills, with marked impairment after the strongest decoction. Blood concentrations were relatively low compared to smoking, and individual variability was high. A CIF greater than 10 correlated with strong intoxication and reduced willingness to drive. |
Abstract
Delta(9)-Tetrahydrocannabinol (THC) is frequently found in the blood of drivers suspected of driving under the influence of cannabis or involved in traffic crashes. The present study used a double-blind crossover design to compare the effects of medium (16.5 mg THC) and high doses (45.7 mg THC) of hemp milk decoctions or of a medium dose of dronabinol (20 mg synthetic THC, Marinol on several skills required for safe driving. Forensic interpretation of cannabinoids blood concentrations were attempted using the models proposed by Daldrup (cannabis influencing factor or CIF) and Huestis and coworkers. First, the time concentration-profiles of THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) (active metabolite of THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in whole blood were determined by gas chromatography-mass spectrometry-negative ion chemical ionization. Compared to smoking studies, relatively low concentrations were measured in blood. The highest mean THC concentration (8.4 ng/mL) was achieved 1 h after ingestion of the strongest decoction. Mean maximum 11-OH-THC level (12.3 ng/mL) slightly exceeded that of THC. THCCOOH reached its highest mean concentration (66.2 ng/mL) 2.5-5.5 h after intake. Individual blood levels showed considerable intersubject variability. The willingness to drive was influenced by the importance of the requested task. Under significant cannabinoids influence, the participants refused to drive when they were asked whether they would agree to accomplish several unimportant tasks, (e.g., driving a friend to a party). Most of the participants reported a significant feeling of intoxication and did not appreciate the effects, notably those felt after drinking the strongest decoction. Road sign and tracking testing revealed obvious and statistically significant differences between placebo and treatments. A marked impairment was detected after ingestion of the strongest decoction. A CIF value, which relies on the molar ratio of main active to inactive cannabinoids, greater than 10 was found to correlate with a strong feeling of intoxication. It also matched with a significant decrease in the willingness to drive, and it matched also with a significant impairment in tracking performances. The mathematic model II proposed by Huestis et al. (1992) provided at best a rough estimate of the time of oral administration with 27% of actual values being out of range of the 95% confidence interval. The sum of THC and 11-OH-THC blood concentrations provided a better estimate of impairment than THC alone. This controlled clinical study points out the negative influence on fitness to drive after medium or high dose oral THC or dronabinol.
Comparable studies
Other randomized controlled trials on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Healthy participants | 2012 | Randomized controlled trial | n = 48 |
| Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Healthy, English-native, right-handed men who had used cannabis 15 times or less in... | 2009 | Double-blind, randomized, placebo-controlled crossover trial | n = 15 |
| Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Healthy male subjects | 2012 | Randomized controlled trial | n = 16 |
| Modulation of Mediotemporal and Ventrostriatal Function in Humans by Δ9-Tetrahydrocannabinol Healthy, native English-speaking, right-handed men of white race/ethnicity who had used... | 2009 | Randomized controlled trial | n = 15 |
| Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Healthy volunteers with a history of light cannabis use | 2019 | Randomized, double-blind, within-subjects crossover | n = 14 |
Citations in the library
Cited by 5
- Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Current Pharmaceutical Design September 12, 2012
- Consommation de cannabis: quels sont les risques ? Annales de Toxicologie Analytique 2008
- Use of psychoactive substances by goods carriage drivers associated with Kerala, India. Traffic injury prevention 2023
- The why behind the high: determinants of neurocognition during acute cannabis exposure. Nature Reviews Neuroscience July 1, 2021
- [Effects of oral cannabis and dronabinol on driving capacity]. Annales pharmaceutiques francaises May 2006