Hallvard Gjerde

Prevalence of alcohol and drugs among Norwegian motor vehicle drivers: A roadside survey

The objective of the study was to determine the prevalence of alcohol, psychoactive medicinal drugs and illegal drugs among drivers in Norwegian road traffic. Drivers of motor vehicles were selected from April 2005 to April 2006 in the south-eastern part of Norway, surrounding, but not including the capital, Oslo. A stratified two-stage cluster sampling procedure was used. In the first stage, random road sites and time intervals were selected, and in the second stage, drivers were stopped by random at those sites and time intervals. Altogether about 12,000 drivers were asked to provide a sample of oral fluid (saliva) and answer a few questions. Samples of oral fluid were obtained from 88% of the drivers, of whom 30% were females and 70% males. The prevalence of each drug was estimated by a weighted average using weights adjusted for under- or over-sampling compared to traffic statistics. Alcohol or drugs were found in oral fluid samples of 4.5% of the drivers; alcohol in 0.4%, psychoactive medicinal drugs in 3.4%, and illegal drugs in 1.0%. Illegal drugs were found more frequently in samples from younger drivers, while psychoactive medicinal drugs were more frequently found in samples from older drivers. Psychoactive medicinal drugs were more prevalent among females than males, among drivers stopped on working days rather than weekends, and among those who reported annual driving distances less than 16,000 km. The drugs found most frequently were zopiclone (1.4%), benzodiazepines (1.4%), codeine (0.8%), tetrahydrocannabinol (0.6%) and amphetamines (0.3%). Two or more drugs were found in 0.6% of the samples, corresponding to 15% of the drug-positive drivers.

Alcohol, psychoactive drugs and fatal road traffic accidents in Norway: A case–control study

A case-control study was conducted on 204 drivers fatally injured in road traffic accidents in south-eastern Norway during the period 2003-2008. Cases from single vehicle accidents (N = 68) were assessed separately. As controls, 10540 drivers selected in a roadside survey in the same geographical area during 2005-2006 were used. Blood samples were collected from the cases and oral fluid (saliva) samples from the controls. Samples were analysed for alcohol, amphetamines, cannabis, cocaine, opioid analgesics, hypnotics, sedatives and a muscle relaxant; altogether 22 psychoactive substances. Equivalent cutoff concentrations for blood and oral fluid were used. The risk for fatal injury in a road traffic accident was estimated using logistic regression adjusting for gender, age, season of the year, and time of the week. The odds for involvement in fatal road traffic accidents for different substances or combination of substances were in increasing order: single drug < multiple drugs < alcohol only < alcohol+drugs. For single substance use: medicinal drug or THC < amphetamine/methamphetamine < alcohol. For most substances, higher ORs were found when studying drivers involved in single vehicle accidents than for those involved in multiple vehicle accidents, but confidence intervals were wider.

Incidence of alcohol and drugs in fatally injured car drivers in Norway

Blood samples from 159 fatally injured drivers from 1989 and 1990, corresponding to 57% of all fatally injured drivers in Norway during this period, were analysed for alcohol and psychoactive drugs. Alcohol was found in 28.3% of the drivers, 27.0% above the legal limit of 0.05%. Drugs were found in 16.4% of the drivers; benzodiazepines and tetrahydrocannabinol were the drugs most frequently found. Among 79 drivers fatally injured in single-vehicle accidents, 41.8% were positive for alcohol and 21.5% were positive for drugs.

Screening for drugs in forensic blood samples using EMIT urine assays.

A screening method for the detection of drugs in haemolysed whole blood has been evaluated. Methanolic extracts of 300 forensic blood samples known to be positive or negative for drugs were analysed with EMIT d.a.u. assay kits for amphetamine, cannabinoids, opiates and benzodiazepines (the latter to analyse for diazepam and the main metabolite N-desmethyldiazepam). There were very few false positive results, except for the amphetamine assay in postmortem blood samples, where 9% were false positive. For amphetamine and cannabinoids a few false negatives were found, these were from samples with very low drug concentrations. No false negatives were found for opiates and diazepam. The present modification of the EMIT d.a.u. method seems to be a good method for screening of drugs in forensic blood samples, except for amphetamine in postmortem samples. The method is simple and requires only 0.5 ml blood.

A comparison of serum carbohydrate-deficient transferrin with other biological markers of excessive drinking

In a study of suggested biological markers of excessive drinking, serum carbohydrate-deficient transferrin (CDT) was compared with serum activities of alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase and gamma glutamyltransferase; serum concentrations of high-density lipoprotein cholesterol; and erythrocyte mean cellular volume. Analytical data were studied in relation to self-reported alcohol consumption during the latest month for the 69 participating subjects. CDT was found to be the most sensitive and most specific marker of excessive drinking, and was also found to be the best marker for monitoring abstinence under treatment of alcoholics.

Detection of drugs of abuse in simultaneously collected oral fluid, urine and blood from Norwegian drug drivers

Blood and urine samples are collected when the Norwegian police apprehend a person suspected of driving under the influence of drugs other than alcohol. Impairment is judged from the findings in blood. In our routine samples, urine is analysed if morphine is detected in blood to differentiate between ingestion of heroin, morphine or codeine and also in cases where the amount of blood is too low to perform both screening and quantification analysis. In several cases, the collection of urine might be time consuming and challenging. The aim of this study was to investigate if drugs detected in blood were found in oral fluid and if interpretation of opiate findings in oral fluid is as conclusive as in urine. Blood, urine and oral fluid samples were collected from 100 drivers suspected of drugged driving. Oral fluid and blood were screened using LC-MS/MS methods and urine by immunological methods. Positive findings in blood and urine were confirmed with chromatographic methods. The analytical method for oral fluid included 25 of the most commonly abused drugs in Norway and some metabolites. The analysis showed a good correlation between the findings in urine and oral fluid for amphetamines, cocaine/benzoylecgonine, methadone, opiates, zopiclone and benzodiazepines including the 7-amino-benzodiazepines. Cocaine and the heroin marker 6-monoacetylmorphine (6-MAM) were more frequently detected in oral fluid than in urine. Drug concentrations above the cut-off values were found in both samples of oral fluid and urine in 15 of 22 cases positive for morphine, in 18 of 20 cases positive for codeine and in 19 of 26 cases positive for 6-MAM. The use of cannabis was confirmed by detecting THC in oral fluid and THC-COOH in urine. In 34 of 46 cases the use of cannabis was confirmed both in oral fluid and urine. The use of cannabis was confirmed by a positive finding in only urine in 11 cases and in only oral fluid in one case. All the drug groups detected in blood were also found in oral fluid. Since all relevant drugs detected in blood were possible to find in oral fluid and the interpretation of the opiate findings in oral fluid was more conclusive than in urine, oral fluid might replace urine in driving under the influence cases. The fast and easy sampling is time saving and less intrusive for the drivers.

Toxicological investigations of drivers killed in road traffic accidents in Norway during 2006–2008

AIM To study the results from the toxicological investigations of drivers of cars and vans who were fatally injured in road traffic accidents in 2006-2008 and discuss the findings in relation to the proposed legal limits and impairment thresholds for drugs. METHODS Analyses for alcohol, illegal drugs and psychoactive medicinal drugs were performed by the Norwegian Institute of Public Health. Information on type of accident (single or multiple vehicles) and type of road (urban or rural) was obtained from Statistics Norway. RESULTS Toxicological analyses were requested for 59% of the fatally injured drivers. Drivers involved in single vehicle accidents were more often subject to toxicological investigations, so were also young male drivers and drivers killed on urban roads. Alcohol or drugs were found in concentrations above the current (for alcohol) or proposed (for drugs) legal limits in samples from 37.8% of the drivers; from 64.3% those killed in single-vehicle accidents and 17.9% of those killed in multiple-vehicle accidents. In total, alcohol was found in 25.0%, illicit drugs in 10.2%, and psychoactive medicinal drugs in 13.8% of the samples. Combinations of alcohol and drugs were found in 5.1% and multiple drugs without alcohol in 6.1% of the samples. The prevalence of alcohol or drugs was higher in samples from males than females, higher in samples from young drivers, and higher in samples from drivers killed during weekends. Two thirds of the drivers with alcohol or drug concentrations above the current or proposed legal limits had concentrations above the proposed high impairment threshold. About 60% of the latter ones were impaired by alcohol only, 20% by drugs in combination with alcohol, and 20% by drugs only, mainly due to multi-drug use. CONCLUSION The use of alcohol or drugs before driving was a significant contributing factor in fatal road traffic accidents, particularly in single vehicle accidents, and particularly among young male drivers. Alcohol was the most significant intoxicant, but multi-substance use was also significantly prevalent. The majority of the drivers with alcohol or drug findings were strongly impaired.

Comparison of drug concentrations between whole blood and oral fluid

The relationship of drug concentrations between oral fluid and whole blood was evaluated by studying the linear correlation of concentrations and calculating the oral fluid to blood concentration ratios (OF/B) for different substances. Paired oral fluid and whole blood samples were collected from volunteers and persons suspected of drug use in four European countries. Oral fluid samples were collected with the Saliva∙Sampler™ device. All samples were analyzed for drugs of abuse and psychoactive medicines with validated gas and liquid chromatography-mass spectrometric methods. The median OF/B ratios were, for amphetamines 19-22, for opioids 1.8-11, for cocaine and metabolites 1.7-17, for tetrahydrocannabinol (THC) 14, for benzodiazepines 0.035-0.33, and for other psychoactive medicines 0.24-3.7. Most of the these results were close to theoretical values based on the physicochemical properties of the drugs and to values presented earlier, but there was a lot of inter-individual variation in the OF/B ratios. For all substances, except for lorazepam (R(2)  = 0.031) and THC (R(2)  = 0.030), a correlation between the oral fluid and whole blood concentrations was observed. Due to large variation seen here, drug findings in oral fluid should not be used to estimate the corresponding concentrations in whole blood (or vice versa). However, detection of drugs in oral fluid is a sign of recent drug use and oral fluid can be used for qualitative detection of several drugs, e.g. in epidemiological prevalence studies. By optimizing the sampling and the analytical cut-offs, the potential of oral fluid as a confirmation matrix could be enhanced.

Simultaneous determination of common benzodiazepines in blood using capillary gas chromatography

Blood samples were extracted with n-butyl acetate, and the extracts analysed by capillary gas chromatography using DB-1 and DB-1701 capillary columns with electron-capture detection. The DB-1701 column was found to give better separation of different benzodiazepines (BZDs). Recoveries ranged from 79 to 98%. Detection limits ranged from 0.005 to 0.015 microM for triazolam and flunitrazepam, and from 0.02 to 0.1 microM for other BZDs. Data on accuracy and precision are given for diazepam, desmethyldiazepam, flunitrazepam and nitrazepam.

Impairment in drivers due to cannabis in combination with other drugs

Blood samples from 425 suspected drugged drivers who were clinically impaired and negative for alcohol were analysed. Fifty-six percent of the samples were positive for tetrahydrocannabinol (THC). Tetrahydrocannabinol-positive blood samples were analysed for amphetamines, barbiturates, benzodiazepines, cocaine metabolites and opiates. Eighty-two percent of the samples were found to be positive for one or more drugs in addition to THC, and the concentrations of these drugs were often high. Thus, THC in combination with other drugs seems to be a much more frequent reason for impairment than THC alone among Norwegian drugged drivers.