Fitness to drive and cannabis: Experimental and real-life case study validation of two blood THCCOOH thresholds to distinguish occasional users from heavy smokers

Détails

ID Serval
serval:BIB_F335ECC92BD4
Type
Actes de conférence (partie): contribution originale à la littérature scientifique, publiée à l'occasion de conférences scientifiques, dans un ouvrage de compte-rendu (proceedings), ou dans l'édition spéciale d'un journal reconnu (conference proceedings).
Sous-type
Abstract (résumé de présentation): article court qui reprend les éléments essentiels présentés à l'occasion d'une conférence scientifique dans un poster ou lors d'une intervention orale.
Collection
Publications
Titre
Fitness to drive and cannabis: Experimental and real-life case study validation of two blood THCCOOH thresholds to distinguish occasional users from heavy smokers
Titre de la conférence
Analytical, Clinical and Forensic Toxicology International Meeting
Auteur(s)
Giroud C., Fabritius M., Augsburger M., Chtioui H., Favrat B.
Adresse
Bordeaux, France, June 10-14, 2014
ISBN
2352-0078
ISSN-L
2352-0078
Statut éditorial
Publié
Date de publication
2014
Volume
26
Série
Toxicologie Analytique et Clinique
Pages
S20
Langue
anglais
Résumé
Introduction: THC-COOH has been proposed as a criterion to help to distinguish between occasional from regular cannabis users. However, to date this indicator has not been adequately assessed under experimental and real-life conditions.
Methods: We carried out a controlled administration study of smoked cannabis with a placebo. Twenty-three heavy smokers and 25 occasional smokers, between 18 and 30 years of age, participated in this study [Battistella G et al., PloS one. 2013;8(1):e52545]. We collected data from a second real case study performed with 146 traffic offenders' cases in which the whole blood cannabinoid concentrations and the frequency of cannabis use were known. Cannabinoid levels were determined in whole blood using tandem mass spectrometry methods.
Results: Significantly high differences in THC-COOH concentrations were found between the two groups when measured during the screening visit, prior to the smoking session, and throughout the day of the experiment. Receiver operating characteristic (ROC) curves were determined and two threshold criteria were proposed in order to distinguish between these groups: a free THC-COOH concentration below 3 μg/L suggested an occasional consumption (≤ 1 joint/week) while a concentration higher than 40 μg/L corresponded to a heavy use (≥ 10 joints/month). These thresholds were successfully tested with the second real case study. The two thresholds were not challenged by the presence of ethanol (40% of cases) and of other therapeutic and illegal drugs (24%). These thresholds were also found to be consistent with previously published experimental data.
Conclusion: We propose the following procedure that can be very useful in the Swiss context but also in other countries with similar traffic policies: If the whole blood THC-COOH concentration is higher than 40 μg/L, traffic offenders must be directed first and foremost toward medical assessment of their fitness to drive. This evaluation is not recommended if the THC-COOH concentration is lower than 3 μg/L. A THC-COOH level between these two thresholds can't be reliably interpreted. In such a case, further medical assessment and follow up of the fitness to drive are also suggested, but with lower priority.
Mots-clé
Toxicology, Forensic Medicine
Création de la notice
07/07/2014 17:12
Dernière modification de la notice
03/03/2018 22:41
Données d'usage