No abstract

Collection of oral fluid (OF) is easy and non-invasive compared to the collection of urine and blood, and interest in OF for drug screening and diagnostic purposes is increasing. A high-throughput ultra-high-performance liquid chromatography-tandem mass spectrometry method for determination of 21 drugs in OF using fully automated 96-well plate supported liquid extraction for sample preparation is presented. The method contains a selection of classic drugs of abuse, including amphetamines, cocaine, cannabis, opioids, and benzodiazepines. The method was fully validated for 200 μL OF/buffer mix using an Intercept OF sampling kit; validation included linearity, sensitivity, precision, accuracy, extraction recovery, matrix effects, stability, and carry-over. Inter-assay precision (RSD) and accuracy (relative error) were <15% and 13 to 5%, respectively, for all compounds at concentrations equal to or higher than the lower limit of quantification. Extraction recoveries were between 58 and 76% (RSD < 8%), except for tetrahydrocannabinol and three 7-amino benzodiazepine metabolites with recoveries between 23 and 33% (RSD between 51 and 52 % and 11 and 25%, respectively). Ion enhancement or ion suppression effects were observed for a few compounds; however, to a large degree they were compensated for by the internal standards used. Deuterium-labelled and C-labelled internal standards were used for 8 and 11 of the compounds, respectively. In a comparison between Intercept and Quantisal OF kits, better recoveries and fewer matrix effects were observed for some compounds using Quantisal. The method is sensitive and robust for its purposes and has been used successfully since February 2015 for analysis of Intercept OF samples from 2600 cases in a 12-month period. Copyright © 2016 John Wiley& Sons, Ltd.

This study describes trends in drug use among drivers suspected of driving under the influence of drugs, apprehended by the police in Norway during 1990-2015. Chromatographically determined toxicological findings in blood samples were retrospectively investigated. Drug findings above defined cut-off concentrations were considered positive; hence making the annual prevalence comparable during the 26 years studied. Blood samples from 112,348 drivers were included, of which 63% were positive for drugs; 43% had combined drug with alcohol or other drugs. In total, 87% of the drug-positive drivers were men, and a higher proportion of them were positive for illicit drugs compared to the women. Benzodiazepines and related drugs were found in 57% of the drug-positive drivers, stimulants in 51%, cannabis (tetrahydrocannabinol, THC) in 34%, and opioids in 18%. The types of benzodiazepines and opioids changed over time. The age distribution also changed; the proportion of drug-positive drivers above 40 years of age increased for all drug classes. The annual number of suspected drug-impaired drivers increased by 122% from 1990 to 1999, and by 54% from 2000 to 2015; the annual number of drug-positive samples increased by 260% from 1990 to 1999, and by 60% from 2000 to 2015. During 2000-2015, an increasing prevalence of amphetamines was found among suspected drug-impaired drivers above age 30; the highest rate of increase was observed among those at or above age 40. In the same period, the prevalence of benzodiazepines and related drugs decreased among all age groups, whereas the prevalence of THC increased; the highest prevalence and rate of increase were among suspected drug-impaired drivers under the age of 30. The results from this study indicate a slight change in the types of drugs used by drivers in Norway.