Elke Raes

Relationship Between Oral Fluid and Blood Concentrations of Drugs of Abuse in Drivers Suspected of Driving Under the Influence of Drugs

In recent years, the interest in the use of oral fluid as a biological matrix has increased significantly, particularly for detecting driving under the influence of drugs (DUID). In this study, the relationship between the oral fluid and the blood concentrations of drugs of abuse in drivers suspected of DUID is discussed. Blood and oral fluid samples were collected from drivers suspected of DUID or stopped during random controls by the police in Belgium, Germany, Finland, and Norway for the ROSITA-2 project. The blood samples were analyzed by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS), sometimes preceded by immunoassay screening of blood or urine samples. The oral fluid samples were analyzed by GC-MS or LC-MS(/MS). Scatter plots and trend lines of the blood and oral fluid concentrations and the median, mean, range, and SD of the oral fluid to blood (OF:B) ratios were calculated for amphetamines, benzodiazepines, cocaine, opiates, and ▵9-2 tetrahydrocannabinol. The ratios found in this study were comparable with those that were published previously, but the range was wider. The OF:B ratios of basic drugs such as amphetamines, cocaine, and opiates were >1 [amphetamine: median (range) 13 (0.5-182), methylenedioxyamphetamine: 4 (1-15), methylenedioxymethamphetamine: 6 (0.9-88), methamphetamine: 5 (2-23), cocaine: 22 (4-119), benzoylecgonine: 1 (0.2-11), morphine: 2 (0.8-6), and codeine: 10 (0.8-39)]. The ratios for benzodiazepines were very low, as could be expected as they are highly protein bound and weakly acidic, leading to low oral fluid concentrations [diazepam: 0.02 (0.01-0.15), nordiazepam: 0.04 (0.01-0.23), oxazepam: 0.05 (0.03-0.14), and temazepam: 0.1 (0.06-0.54)]. For tetrahydrocannabinol, an OF:B ratio of 15 was found (range 0.01-569). In this study, the time of last administration, the dose, and the route of administration were unknown. Nevertheless, the data reflect the variability of the OF:B ratios in drivers thought to be under the influence of drugs. The wide range of the ratios, however, does not allow reliable calculation of the blood concentrations from oral fluid concentrations.

Cannabis et conduite automobile: la situation en Europe

Resume En Europe, trois millions de personnes consomment quotidiennement du cannabis. Des enquetes ont demontre que plus des deux tiers des consommateurs de drogue conduisent apres avoir fume du cannabis. Les etudes epidemiologiques demontrent que le pourcentage de la population generale des conducteurs positifs au cannabis varie entre 0,5 % et 8,2 %. Chez les conducteurs blesses ou decedes suite a un accident, le pourcentage varie respectivement de 3,3 % a 10 % et de 2,2 % a 8,4 %. Enfin, des pourcentages tres eleves sont trouves dans les etudes qui ont recherche les drogues chez les conducteurs suspectes de conduite sous l′influence des drogues : plus de 50 % en Allemagne, en Autriche, en Belgique, au Royaume-Uni et en Suisse. Six pays europeens ont adopte une legislation analytique ou « per se » et les seuils de positivite varient entre 0,3 et 2 ng/mL de THC. Aux Pays-Bas, des etudes experimentales effectuees apres administration de cannabis ont clairement demontre les effets deleteres, en particulier en cas de consommation simultanee de cannabis et d′alcool. Differents projets de recherche finances par l′Union europeenne ont etudie les aspects epidemiologiques (IMMORTAL), la detection par tests psychotechniques (CERTIFIED) et la detection de drogues au bord de la route (ROSITA et ROSITA-2).

Chapter 19 Drugs and driving

Publisher Summary This chapter discusses drugs and driving. Every year, more than a million people are killed and many millions more are injured in traffic crashes. Traffic crashes are the consequence of many factors, which can be classified into three categories: the road, the vehicle, and the driver. A crash is rarely attributable to only one factor; therefore, it is very difficult to determine in what percentage of crashes alcohol or drugs have contributed. Toxicological analysis can be performed on samples of drivers suspected of “driving under the influence of drugs” (DUID) and drivers injured or killed as a consequence of a traffic accident, and on samples of drivers that were collected during roadside surveys. A typical procedure of toxicological analysis involves two steps: screening and confirmation. Usually an immunoassay followed by a chromatographic method is performed: the first allows for a preliminary monitoring of a large number of samples in a reduced period of time; while the second step provides the required specificity. There has recently been an increase in the repertoire of immunoassays now available with the techniques becoming increasingly more specific for the drugs and/or metabolites being monitored.