First nationwide study on driving under the influence of drugs in Switzerland

A scoping review of motor vehicle operator performance assessments for benzodiazepine receptor agonists

Background

Benzodiazepines and Z-drugs (e.g., zopiclone, zolpidem) (benzodiazepine receptor agonists or BZRAs), are prescribed for anxiety and insomnia disorders. However, they are not indicated as first line therapies for long-term management due to harms and efficacy limitations. BZRAs have also been associated with traffic accident risks. Patients taking BZRAs are told to consult with health care providers regarding motor vehicle operation safety. However, advice on driving is variable. The objective of this scoping review is to identify, map, and characterize the evidence for assessments that measure driving performance in people taking BZRAs.

Methods

Embase (Elsevier), MEDLINE (Ovid), and PsycINFO (EBSCO) were searched. Covidence was used for screening. Each stage of screening included two independent reviewers. A REDCap database was used for data extraction by two independent reviewers. Results were tabulated and summarised as a narrative.

Results

Driving performance was assessed with 20 unique BZRAs across 183 studies (n = 92 experimental; n = 91 observational) in 178 publications. Zopiclone was the most studied. In experimental studies, the Standard Deviation of Lateral Position (SDLP) was used most often (n = 54, 62 %) and many studies (n = 35, 38 %) were conducted in the Netherlands. For observational studies, biological detection (e.g., urine, blood) (n = 73, 80 %) followed by prescription drug/dispensing records (n = 17, 19 %) were the most common impairment measures and Norway (n = 20) is where most studies took place. In experimental studies, most (n = 89, 97 %) were conducted using only one driving setting. Simulated driving in a car (n = 36) and road driving in traffic (n = 36) were common as compared to nontraffic driving course (n = 8) and simulated driving (n = 9). In experimental studies, seventy-eight of the 92 studies (85 %) had at least one measure that identified impairment.

Conclusions

BZRA effects on motor vehicle driving performance have been studied using heterogenous protocols with multiple measures and settings, ranging from simulation to authentic traffic situations in experimental studies to biological detection and dispensing records in observational studies. Many BZRAs have been studied but study representation does not match prescribing pattern prevalence. The interpretation and contextualization of results for clinical practice is challenging due to the complexity (i.e., protocols, measures, settings). Future work in this area should work to improve knowledge translation of results so information is more readily accessible and applicable to health care providers and patients.

Driving under the influence of cocaine and MDMA: Relationship between blood concentrations and results from clinical test of impairment

The general use of cocaine is increasing in recent years, while the trend for 3,4-methylenedioxymethamphetamine (MDMA) is less clear. The relationship between blood concentrations and impairment is poorly understood, which complicates interpretation. The aims of this study were to report prevalence and blood concentrations of cocaine and MDMA in drugged drivers, and to investigate the relationship between blood concentrations and impairment. Samples of whole blood were collected from apprehended drivers in the period 2000-2022, and a clinical test of impairment (CTI) was simultaneously performed. The samples were initially analyzed for cocaine and MDMA using gas chromatography-mass spectrometry (until 2009 and 2012, respectively), and later using ultra-high-performance liquid chromatography-tandem mass spectrometry. Overall, cocaine was detected in 2,331 cases and MDMA in 2,569 cases. There were 377 and 85 mono cases of cocaine and MDMA, respectively. In the mono cases, the median cocaine concentration was 0.09 mg/L (range: 0.02-1.15 mg/L), and 54% of the drivers were clinically impaired. The median MDMA concentration was 0.19 mg/L (range: 0.04-1.36 mg/L), and 38% were clinically impaired. There was a statistically significant difference in the median cocaine concentration between drivers assessed as not impaired (0.07 mg/L) and drivers assessed as impaired (0.10 mg/L) (P = 0.009). There was also a significant effect of the blood concentration of cocaine (adjusted odds ratio [aOR] = 6.42, 95% confidence interval [CI] = 1.13-36.53, P = 0.036) and driving during the evening/night-time (aOR = 2.17, 95% CI = 1.34-3.51, P = 0.002) on the probability of being assessed as impaired on the CTI. No significant differences were found for MDMA. Many drivers are not assessed as impaired on a CTI following cocaine or especially MDMA use. For cocaine, a relationship between blood concentrations and impairment was demonstrated, but this could not be shown for MDMA.

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Effects of 3,4-methylenedioxymethamphetamine and methamphetamine on motor vehicle driving performance: A systematic review of experimental and observational studies

Methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) are common drugs of abuse and driving under their influence may occur in 1 million people yearly in the United States. This systematic review fills the currently unmet need in understanding the effects of METH and MDMA on motor vehicle driving performance (MVP) and provides insight into the forensic community. A PubMed search on September 24, 2020, for experimental and observational studies, which evaluated the impact of METH and MDMA on MVP was performed. After a review of 208 abstracts, 103 were considered potentially interesting and full texts were obtained. After the exclusion of non-English articles, review articles, single case reports, and articles which did not evaluate METH or MDMA on MVP, a total of nine experimental studies, 10 traditional observational studies, and 35 case series were included. The clinical rigor of experimental studies was evaluated using the Jadad scale. Experimental studies often demonstrated no significant MVP safety signals for METH or MDMA use, which was contrary to the overwhelming MVP safety risks found in observational studies. Common driving behaviors while using METH or MDMA include: errors in judgment, traveling at high speeds, failure to stop, merging inappropriately, lane weaving, and crashes. Limitations of experimental studies that led to dissimilar MVP outcomes from observational studies include: the common use of driving simulators, as opposed to actual driving examinations, and doses of METH or MDMA administered may not be representative of blood concentrations seen in observational studies. This systematic review has no funding source and was not registered.

Randomly controlled drivers using minimally invasive sampling: assessment of drug prevalence in Western Switzerland over two time periods

BACKGROUND

According to the World Health Organization, road traffic injuries lead to 1.3 million deaths each year and represent the leading cause of death for young adults under 30 years old. The use of psychoactive substances, including alcohol, drugs and pharmaceuticals, is a well-known risk factor for road traffic injuries. Our study aims to assess the prevalence of substances consumed by drivers in western Switzerland. Such studies are pivotal to improving prevention and developing public awareness campaigns.

METHODS

To assess the prevalence of psychoactive substances among drivers, roadside controls were performed in collaboration with local police, using their classical sampling procedures to detect drivers under the influence of drugs or alcohol over two time periods (P1: 2006-2008, P2: 2017-2020). When impaired driving was not suspected by the police, minimally invasive sampling strategies (i.e., oral fluids during P1 and dried blood spots during P2) were performed on volunteer drivers after a road safety survey. A posteriori analyses and statistical interpretation were then performed.

RESULTS

Among the 1605 drivers included in the study, 1048 volunteers provided an oral fluid sample, while 299 provided a dried blood spot sample. The percentage of drivers testing positive for at least one substance that can impact driving abilities was stable over time, with a rate of 10.5% positivity measured over both periods. Considering the different categories of substances, a slight variation was observed between both periods, with 7.6 and 6.3% of pharmaceuticals and 3.6 and 4.9% of illicit drugs for P1 and P2, respectively. Regarding the consumption of illicit drugs, the highest percentage of positivity was measured in biological fluids of drivers under the age of 35, during nights and week-ends, periods which are considered particularly prone to fatal accidents for this age group. Disturbingly, the road safety survey highlighted that drivers' perception of the risk of getting positively controlled while driving after drug consumption is low (3.3 on a 1-to-10 scale, N = 299).

CONCLUSION

The number of positive cases measured in voluntary drivers who passed the preliminary police check demonstrates the importance of systematic biofluid sampling strategies regarding driving under the influence of psychoactive substances. Although the number of fatal road accidents globally has decreased over time, the results of this study reveal the need for both better prevention and deterrent processes that could potentially reduce the risk of fatal road accidents associated with drug consumption.

Trends in Prescription Opioid Use in Motor Vehicle Crash Injuries in the United States: 2014-2018

Motor vehicle crashes (MVC) cause over three million people to be nonfatally injured each year in the United States alone. We investigated trends and patterns in prescription opioid usage among nonfatal MVC injuries in 50 states in the US and the District of Columbia from 2014 to 2018. All emergency department visits for an MVC event (N = 142,204) were identified from the IBM^® MarketScan^® Databases. Using log-binomial regression models, we investigated whether the prevalence of prescription opioids in MVC injuries varied temporally, spatially, or by enrollees' characteristics. Adjusting for age, relationship to the primary beneficiary, employment status, geographic region, and residence in metropolitan statistical area, the prevalence decreased by 5% (95% CI: 2-8%) in 2015, 18% (95% CI: 15-20%) in 2016, 31% (95% CI: 28-33%) in 2017, and 49% (95% CI: 46-51%) in 2018, compared to 2014. Moreover, the prevalence decreased by 28% (95% CI: 26-29%) after the publication of the CDC Guidelines for Prescribing Opioids for Chronic Pain. Spatial variations were observed in the prevalence and temporal trend of prevalence. The decreasing trend in the prevalence of prescription opioids in MVC is consistent with the decrease in the dispensing rate of opioids and the percentage of high-dosage opioids in the study population.

Applications of Cannabis Sativa L. in Food and Its Therapeutic Potential: From a Prohibited Drug to a Nutritional Supplement

Hemp (Cannabis sativa L.) is a herbaceous anemophilous plant that belongs to the Cannabinaceae family. The cannabis seed (hemp) has long been utilized as a food source and is commercially important as an edible oil source. In this review, the positive and negative health effects of cannabis, the relationship between cannabis and various diseases, and the use of cannabis in various food products have been discussed. In addition, the scientific literature on the potential use of cannabis and its derivatives as a dietary supplement for the prevention and treatment of inflammatory and chronic degenerative diseases in animals and humans has been reviewed. Cannabis is being developed as a key ingredient in a variety of food items, including bakery, confectionery, beverages, dairy, fruits, vegetables, and meat. Hemp seeds are high in readily digestible proteins, lipids, polyunsaturated fatty acids (PUFA), insoluble fiber, carbs, and favorable omega-6 PUFA acid to omega-3 PUFA ratio and have high nutritional value. The antioxidants of cannabis, such as polyphenols, help with anxiety, oxidative stress, and the risk of chronic illnesses, including cancer, neurological disorders, digestive problems, and skin diseases. Cannabis has been shown to have negative health impacts on the respiratory system, driving, and psychomotor functions, and the reproductive system. Overall, the purpose of this research is to stimulate more in-depth research on cannabis's adaptation in various foods and for the treatment of chronic illnesses.

Risk-taking behaviors of e-scooter users: A survey in Paris

Risk-taking behavior is often held responsible for increased crash involvement. We designed and undertook a face-to-face road survey (N = 459) in order to explore incident involvement history, driving attitudes and perceived risk among e-scooter users is Paris, France. Three risk factors were specifically explored: (i) riding after having consumed alcohol, (ii) riding after having consumed drugs, and (iii) using the smartphone while riding. The relationship between these factors and user attributes (such as age and gender) and travel behavior (such as frequency of e-scooter usage and trip duration) was examined using logit and mixed logit specifications and a structural equation model. Empirical evidence suggests that it is more likely for young and male riders to develop risky behaviors. Longer trip durations seem to be associated with risk-taking behaviors.

Suspicion of driving under the influence of alcohol or drugs: Cross sectional analysis of drug prevalence in the context of the Swiss legislation

Driving under the influence of alcohol and drugs (DUID) is a major field of study to improve road safety. In Switzerland, during controls whether or not they follow an accident, the police can request toxicological analysis targeted either on alcohol only (ALC cases), or on drugs and alcohol (DUID cases). To evaluate both the drugs consumption on the road and whether or not these requests are well correlated with toxicological results, we built a database recording 4003 offenders (3443 males, 550 females) over a two-year period (2018-2019) in Western Switzerland. ALC case samples were then analyzed to target other substances than ethanol. We found one or more psychoactive drugs in 89% of DUID cases and alcohol alone was found in 56% of ALC cases. In ALC cases, alcohol alone was found in 72% of non-accident cases and in 52% of accident cases. This highlights an influence of accident context, inducing a too high suspicion of alcohol after accidents, and therefore an underestimation of the prevalence of other drugs. The most frequently detected drugs in DUID cases were cannabinoids (58%), ethanol (30%), cocaine (21%), benzodiazepines (11%), amphetamines (7%), opiates (6%), and antidepressants (5%). For the ALC cases, the drugs found were ethanol (84%), cannabinoids (13%), benzodiazepines (9%), antidepressants (6%), opiates (5%), cocaine (4%), methadone (3%), and amphetamines (1%). Prescription drugs, such as benzodiazepines, were common in accidents (22%) but rare in non-accidents DUID cases (5%). Thus, these drugs highly impact driving skills while being hard to suspect. This is of first concern as prescription drugs are largely found in poly-drug consumption, especially in combination with alcohol in accident cases. This emphasizes the emerging issue of prescription drugs and should motivate a strategy of prevention focused on the noxious effect of combining alcohol and prescription drugs on driving skills.

Summary statistics for drugs and alcohol concentration recovered in post-mortem femoral blood in Western Switzerland

In post-mortem investigations of fatal intoxication, it is challenging to determine which drug(s) were responsible for the death, and which drugs did not. This study aims to provide post-mortem femoral blood drug levels in lethal intoxication and in post-mortem control cases, where the cause of death was other than intoxication. The reference values could assist in the interpretation of toxicological results in the routine casework. To this end, all post-mortem toxicological results in femoral blood from 2011 to 2017 in Western Switzerland were considered. A full autopsy with systematic toxicological analysis (STA) was conducted in all cases. Results take into account the cause of death classified into one of four categories (as published by Druid and colleagues): I) certified intoxication by one substance alone, IIa) certified intoxication by more than one substance, IIb) certified other causes of death with incapacitation due to drugs, and III) certified other causes of death without incapacitation due to drugs. This study includes 1 990 post-mortem cases where femoral blood was analysed. The material comprised 619 women (31%) and 1 371 men (69%) with a median age of 50 years. The concentrations of the 32 most frequently recorded substances as well as alcohol are discussed. These include 6 opioids and opiates, 3 antidepressants, 6 neuroleptics and hypnotics, 1 barbiturate, 11 benzodiazepines (and related drugs), 2 amphetamine-type stimulants, cocaine, paracetamol, and tetrahydrocannabinol (THC). The most common substances that caused intoxication alone were morphine, methadone, ethanol, tramadol, and cocaine. The post-mortem concentration ranges for all substance are categorized as I, IIa, IIb, or III. Statistical post-mortem reference concentrations for drugs are discussed and compared with previously published concentrations. This study shows that recording and classifying cases is time-consuming, but it is rewarding in a long-term perspective to achieve a more reliable information about fatal and non-fatal blood concentrations.

Driving Under the Influence of Drugs: A Single Parallel Monitoring-Based Quantification Approach on Whole Blood

Driving under the influence of psychoactive substances is a major cause of motor vehicle crashes. The identification and quantification of substances most frequently involved in impaired-driving cases in a single analytic procedure could be an important asset in forensic toxicology. In this study, a highly sensitive and selective liquid chromatography (LC) approach hyphenated with Orbitrap high-resolution mass spectrometry (HRMS) was developed for the quantification of the main drugs present in the context of driving under the influence of drugs (DUID) using 100 μL of whole blood. This procedure involves a simple sample preparation and benefit from the selectivity brought by parallel reaction monitoring (PRM) allowing to solve most DUID cases using a single multi-analyte injection. The method was fully validated for the quantification of the major classes of psychoactive substances associated with impaired-driving (cannabinoids, cocaine and its metabolites, amphetamines, opiates and opioids, and the major benzodiazepines and z-drugs). The validation guidelines set by the “Société Française des Sciences et des Techniques Pharmaceutiques” (SFSTP) were respected for 22 psychoactive substances using 15 internal standards. Trueness was measured to be between 95.3 and 107.6% for all the tested concentrations. Precision represented by repeatability and intermediate precision was lower than 12% while recovery (RE) and matrix effect (ME) ranged from 49 to 105% and from −51 to 3%, respectively. The validated procedure provides an efficient approach for the simultaneous and simple quantification of the major drugs associated with impaired driving benefiting from the selectivity of PRM.

Alcohol and illicit drugs in drivers involved in road traffic crashes in Italy. An 8-year retrospective study

This study aims to investigate the prevalence of alcohol and drugs of abuse in Italian drivers involved in road traffic crashes between 2011 and 2018. Toxicological analyses were performed on the whole blood of 7593 injured drivers. Alcohol and illicit drugs, namely tetrahydrocannabinol (THC; cut-off 2ng/ml), cocaine (cut-off 10ng/ml), illicit opiates (cut-off 10ng/ml) and amphetamines (amphetamine, methamphetamine, MDMA, MDA; cut-off 20ng/ml) were investigated. The age and gender of the driver, the time of the crash (weekend/weekday and day/night), the road crash year and Blood Alcohol Concentration (BAC) were also considered. The 16.2% of samples tested positive for alcohol, 2.5% for cocaine, followed by opiates (2.0%), cannabinoids (1.5%), and amphetamines (0.5%). The overall prevalence of alcohol and drugs was lower than those reported in previous epidemiological studies of the DRUID project. The year 2011 showed the highest prevalence of drug-positive cases (24.1%), while the lowest prevalence was found in 2016 (16.8%), after the update of the Road Traffic Law (RTL) that increased punishments for driving under the influence. A progressive increase in the number of alcohol-positive female drivers was observed from 2011 to 2018, and the highest prevalence was found in the 26-35-year-old age range. Illicit drugs showed the highest overall prevalence in drivers <26 years of age but, if considering single drugs, cocaine and opiates were mostly found in subjects older than 36 years of age. A higher percentage of drug-positive drivers was found on weekend nights for alcohol and on both weekend and weekday nights for drugs. The types of drugs used by drivers did not change during the studied period.

Driving Under the Influence of Cannabis: A Framework for Future Policy

Marijuana is the most widely consumed illicit substance in the United States, and an increasing number of states have legalized it for both medicinal and recreational purposes. As it becomes more readily available, there will be a concurrent rise in the number of users and, consequently, the number of motor vehicle operators driving under the influence. This article examines the cognitive and psychomotor effects of cannabis, as well as current policy concerning driving under the influence of drugs. The authors performed a MEDLINE search on the epidemiology of cannabis use, its cognitive and psychomotor effects, and policies regarding driving under the influence of drugs. Twenty-eight epidemiological studies, 16 acute cognitive and psychomotor studies, 8 chronic cognitive and psychomotor studies, and pertinent state and federal laws and policies were reviewed. These search results revealed that marijuana use is associated with significant cognitive and psychomotor effects. In addition, the legalization of marijuana varies from state to state, as do the laws pertaining to driving under the influence of drugs. Marijuana is a commonly found illicit substance in motor vehicle operators driving under the influence of drugs. Current evidence shows that blood levels of tetrahydrocannabinol do not correlate well with the level of impairment. In addition, although acute infrequent use of cannabis typically leads to cognitive and psychomotor impairment, this is not consistently the case for chronic heavy use. To establish the framework for driving under the influence of cannabis policy, we must review the current published evidence and examine existing policy at state and federal levels.

Differential effects of psychoactive substances on human wildtype and polymorphic T356M dopamine transporters (DAT)

Many psychoactive substances affect the human dopamine (DA) reuptake transporter (hDAT). Polymorphisms in the encoding gene could affect the functionality of the transporter and consequently alter effects of psychotropic and recreational drugs. Recently, a T356 M single nucleotide polymorphism in the human SLC6A3 gene was described, which resulted in functional impairments of DA uptake. Therefore, we investigated the effects of 10 psychoactive substances (0.01-1000 μM)) on DA uptake in human embryonic kidney (HEK) 293 cells transiently overexpressing wildtype (WT) or T356 M hDAT. Our data shows that T356 M hDAT has a 3 times lower V_max and a 3 times higher K_m compared to WT hDAT. Additionally, all psychoactive substances inhibited DA uptake by T356 M and WT hDAT. The DA reuptake inhibitors (methylphenidate, cocaine, and bupropion) inhibited DA uptake by WT hDAT most potently, followed by amphetamine-type stimulants [4-fluoroamphetamine (4-FA), amphetamine and MDMA], selective serotonin reuptake inhibitors (SSRI; fluoxetine and citalopram) and arylcyclohexylamines [methoxetamine (MXE) and ketamine]. Compared to DA uptake by WT hDAT, bupropion, methylphenidate, cocaine, and MXE less potently inhibited DA uptake by T356 M hDAT, while citalopram more potently inhibited uptake. The differences in IC₅₀ values between T356 M and WT hDAT were considerable (3-45 fold). As such, the presence of this polymorphism could affect treatment efficiency with these substances as well as susceptibly for toxicity and addiction for individuals carrying this polymorphism.

The Dangerous Pattern of Concurrent Use of Alcohol and Cocaine Among Drunk-Drivers of Northeast Italy

Aim

To estimate the prevalence of drug and polydrug use among drunk-drivers during the driving license regranting program, in order to assess the inclusion of toxicological tests on hair and urine samples in the systematic methodology in this category of subjects.

Short summary

A total of 2160 drunk-drivers were tested for alcohol and drugs during driving license regranting. Thirty-one subjects showed alcohol use, 212 illicit drug use and, among these, 131 were polydrug users. Nineteen different patterns of drug and polydrug use were found. Cocaine was detected in 165 subjects.

Methods

The study was performed on 2160 drunk-drivers examined at Legal Medicine and Toxicology Unit of the University of Padova, in a 3-year-period (2014-2017). The positivity for one or more illicit drugs in hair or urine samples was confirmed by LC/MS and GC/MS methods. Chi-square test, Fischer's exact test and Cochran-Armitage Trend test were used to study the correlation between general characteristics of the examined sample and the presence of drug/polydrug use.

Results

Thirty-one subjects showed alcohol use, 212 illicit drug use and, among these, 131 were polydrug users. Nineteen different patterns of drug and polydrug use were found. Cocaine was detected in 165 subjects in whom 122 showed a concurrent use of alcohol and cocaine, identified through the detection of cocaethylene in hair samples. No significant association and/or trends between drug/polydrug use and the general characteristics of the sample were detected.

Conclusions

The results show that drug and polydrug use among drunk-drivers should be subjected to toxicological as well as alcohological monitoring, especially in the regranting procedure. The implementation of this procedure could improve the knowledge of dimensions of the issue, providing a powerful means for the reduction of phenomenon of driving under the influence of alcohol and drugs.

Driving under the influence of drugs: Prevalence in road traffic accidents in Italy and considerations on per se limits legislation

OBJECTIVE

The objective of this study was to present the prevalence and concentrations of drugs in blood samples of drivers involved in road traffic accidents (RTAs) and to discuss the effects of adopting different concentration cutoff values proposed or applied in other European countries on the number of driving under the influence of drugs (DUID) offenses.

METHODS

Blood samples from drivers involved in RTAs in Padova province from 2014 to 2017 were analyzed for the presence of alcohol and drugs. The prevalence of positive subjects was reported for each substance adopting the limits of quantification (LOQs) of our laboratory and the concentration cutoff values proposed and/or used in other European countries. The reduction of cases of driving under the influence of illicit drugs in applying different cutoffs was calculated.

RESULTS

Four thousand four hundred forty-three blood samples were analyzed: 23.7% were positive for alcohol and 19.9% for psychoactive drugs, with prevalences of polydrug and alcohol-drug abuse of 4.5 and 6%, respectively. The most frequently detected drugs were cannabinoids (9.7%) and cocaine (7.2%), followed by benzodiazepines (4.1%), opiates (1.9%), and other opioids (1.7%). Barbiturates, amphetamines, and ketamine were identified in a much smaller number of cases. The overall decrease in DUID cases when adopting different cutoffs with respect to cases above the LOQs was between 8 and 84%. The adoption of high LOQs such as those used in the European Union's research project on Driving Under the Influence of Drugs, Alcohol and Medicines (DRUID) decreases the hypothetical number of DUID offenses by a quarter, and per se limits proposed as broadly equivalent to a blood alcohol concentration (BAC) between 0.2 and 0.8 g/L dramatically reduce the cases of DUID (cocaine -81%, cannabis -79%, opioids -97%, opiates -96%, and amphetamines -77%); no ketamine-positive samples were above the cutoff.

CONCLUSIONS

The implementation of high analytical limits or per se limits based on impairing concentrations in the Italian legislation could result in the prosecution of a much lower number of drugged drivers involved in RTAs, with a decrease from 25% to more than 80% depending on the limits.

Neurotoxicity screening of new psychoactive substances (NPS): Effects on neuronal activity in rat cortical cultures using microelectrode arrays (MEA)

While the prevalence and the use of new psychoactive substances (NPS) is steadily increasing, data on pharmacological, toxicological and clinical effects is limited. Considering the large number of NPS available, there is a clear need for efficient in vitro screening techniques that capture multiple mechanisms of action. Neuronal cultures grown on multi-well microelectrode arrays (mwMEAs) have previously proven suitable for neurotoxicity screening of chemicals, pharmaceuticals and (illicit) drugs. We therefore used rat primary cortical cultures grown on mwMEA plates to investigate the effects of eight NPS (PMMA, α-PVP, methylone, MDPV, 2C-B, 25B-NBOMe, BZP and TFMPP) and two 'classic' illicit drugs (cocaine, methamphetamine) on spontaneous neuronal activity. All tested drugs rapidly and concentration-dependently decreased the weighted mean firing rate (wMFR) and the weighted mean burst rate (wMBR) during a 30 min acute exposure. Of the 'classic' drugs, cocaine most potently inhibited the wMFR (IC₅₀ 9.8 μM), whereas methamphetamine and the structurally-related NPS PMMA were much less potent (IC₅₀ 100 μM and IC₅₀ 112 μM, respectively). Of the cathinones, MDPV and α-PVP showed comparable IC₅₀ values (29 μM and 21 μM, respectively), although methylone was 10-fold less potent (IC₅₀ 235 μM). Comparable 10-fold differences in potency were also observed between the hallucinogenic phenethylamines 2C-B (IC₅₀ 27 μM) and 25B-NBOMe (IC₅₀ 2.4 μM), and between the piperazine derivatives BZP (IC₅₀ 161 μM) and TFMPP (IC₅₀ 19 μM). All drugs also inhibited the wMBR and concentration-response curves for wMBR and wMFR were comparable. For most drugs, IC₅₀ values are close to the estimated human brain concentrations following recreational doses of these drugs, highlighting the importance of this efficient in vitro screening approach for classification and prioritization of emerging NPS. Moreover, the wide range of IC₅₀ values observed for these and previously tested drugs of abuse, both within and between different classes of NPS, indicates that additional investigation of structure-activity relationships could aid future risk assessment of emerging NPS.

Continuity of drunk and drugged driving behaviors four years post-college

BACKGROUND

Driving under the influence of alcohol is a leading cause of injury and premature death among young adults, and college-educated individuals are at particularly high risk. Less is known about driving under the influence of other drugs, which is on the rise.

METHOD

This study describes prospective seven-year trends in alcohol and other drug (AOD)-involved driving among a young-adult sample beginning with their second year of college (i.e., Years 2-8), and documents the extent of continuity in such behaviors across time. Originally recruited as incoming first-year students at one large public university, participants (n=1194) were interviewed annually about how frequently they drove while drunk/intoxicated (DWI), after drinking any alcohol (DAD), and/or while under the influence of other drugs (DD). Follow-up rates were high (>75% annually).

RESULTS

Among participants with access to drive a car, annual prevalence peaked in Year 4 (modal age 21) for both DWI (24.3%_wt) and DD (19.1%_wt) and declined significantly thereafter through Year 8 (both ps<0.05). DAD was far more prevalent than DWI or DD, increasing from 40.5%_wt in Year 2 to 66.9%_wt in Year 5, and plateauing thereafter. Among marijuana-using participants, likelihood of DD was consistently greater than the likelihood of DWI among Heavy Episodic and Light-to-Moderate drinkers, and it declined significantly during Years 5-8 (p<0.05).

CONCLUSION

Post-college declines in heavy drinking and DWI prevalence were encouraging but did not necessarily translate to reductions in likelihood of engaging in DWI, depending on drinking pattern. College-educated individuals represent an important target for AOD-involved driving prevention.

Effect fingerprinting of new psychoactive substances (NPS): What can we learn from in vitro data?

The use of new psychoactive substances (NPS) is increasing and currently >600 NPS have been reported. However, limited information on neuropharmacological and toxicological effects of NPS is available, hampering risk characterization. We reviewed the literature on the in vitro neuronal modes of action to obtain effect fingerprints of different classes of illicit drugs and NPS. The most frequently reported NPS were selected for review: cathinones (MDPV, α-PVP, mephedrone, 4-MEC, pentedrone, methylone), cannabinoids (JWH-018), (hallucinogenic) phenethylamines (4-fluoroamphetamine, benzofurans (5-APB, 6-APB), 2C-B, NBOMes (25B-NBOMe, 25C-NBOMe, 25I-NBOMe)), arylcyclohexylamines (methoxetamine) and piperazine derivatives (mCPP, TFMPP, BZP). Our effect fingerprints highlight the main modes of action for the different NPS studied, including inhibition and/or reversal of monoamine reuptake transporters (cathinones and non-hallucinogenic phenethylamines), activation of 5-HT₂receptors (hallucinogenic phenethylamines and piperazines), activation of cannabinoid receptors (cannabinoids) and inhibition of NDMA receptors (arylcyclohexylamines). Importantly, we identified additional targets by relating reported effect concentrations to the estimated human brain concentrations during recreational use. These additional targets include dopamine receptors, α- and β-adrenergic receptors, GABA_Areceptors and acetylcholine receptors, which may all contribute to the observed clinical symptoms following exposure. Additional data is needed as the number of NPS continues to increase. Also, the effect fingerprints we have obtained are still incomplete and suffer from a large variation in the reported effects and effect sizes. Dedicated in vitro screening batteries will aid in complementing specific effect fingerprints of NPS. These fingerprints can be implemented in the risk assessments of NPS that are necessary for eventual control measures to reduce Public Health risks.

Prevalence of drugs in oral fluid from truck drivers in Brazilian highways

Traffic accidents are responsible for 1.25 million deaths worldwide and are the most common cause of death among those aged 15-29 years. In Brazil, traffic accidents caused more than 44,000 deaths in 2014. The use of psychoactive drugs is an important risk factor for being involved in traffic accidents. Previous studies have found that psychoactive substances are commonly used by truck drivers in Brazil to maintain their extensive work schedule and stay awake while driving during nighttime hours. The state of Sao Paulo is one of the most important states regarding goods transportation. Important highways cross through Sao Paulo to other regions from Brazil and to other countries in Latin America. This study aims to determine the prevalence of illicit drug use by truck drivers in the state of Sao Paulo through toxicological analyses of oral fluid. Truck drivers were randomly stopped by police officers on federal roads during morning hours. Oral fluid samples were collected using the Quantisal™ device. In addition, a questionnaire concerning sociodemographic characteristics and health information was administered. Oral fluid samples were screened for amphetamine, cocaine, and tetrahydrocannabinol (Δ9-THC) by ELISA and the confirmation was performed using ultra performance liquid chromatography with tandem mass spectrometry detection (UPLC-MS/MS). Of the 764 drivers stopped, 762 agreed to participate. The participants were driving an average of 614km and 9.4h a day. Of the total samples, 5.2% (n=40) tested positive for drugs. Cocaine was the most frequently found drug (n=21), followed by amphetamine (n=16) and Δ9-THC (n=8). All drivers were men with an average age of 42.5 years. With these results we were able to verify that many truck drivers were still consuming psychoactive drugs while driving, and cocaine was the most prevalent one. This reinforces the need for preventive measures aimed at controlling the use of illicit drugs by truck drivers in Brazil.

Could Google Trends Be Used to Predict Methamphetamine-Related Crime? An Analysis of Search Volume Data in Switzerland, Germany, and Austria

Objective

To compare the time trends of Google search interest in methamphetamine and criminal offences related to this drug.

Methods

Google Trends data for the search term "meth" was compared to methamphetamine-related crime statistics (incl. use, possession, and dealing) in Switzerland, Germany, and Austria for the years 2004–2016. Google data was availably monthly. Crime data was available yearly, and monthly values were imputed.

Results

On the country level, internet search trends for "meth" roughly paralleled relevant criminal activity. State-level data, which was available for Austria, showed more heterogeneity. Cross-correlations for yearly data almost always peaked at a lag time of 0 and coefficients were mostly between 0.7 and 1.0 on the country level, and between 0.5 to 1.0 on the state level. Monthly cross-correlations based on imputed values were substantially lower, ranging from 0 to 0.6.

Conclusions

These results encourage the further evaluation by law enforcement authorities of Google search activity as a possible predictor of methamphetamine-related crime. However, several limitations, in particular the crude temporal resolution of available crime data, precluded a detailed assessment of the relationship between internet search trends and the development of methamphetamine-related crime in central Europe.

Predominance of alcohol and illicit drugs among traffic accidents fatalities in an urban area of Brazil

OBJECTIVE

The objective of this study was to determine the prevalence of alcohol and illicit drug use among victims of fatal traffic accidents in the Metropolitan Region of Vitória, Brazil, during the period 2011-2012.

METHODS

Blood samples were collected and analyzed for the presence of drugs from 391 deceased victims of traffic crashes that occurred in the Metropolitan Region of Vitória, Brazil. The victims included drivers, passengers, and pedestrians. Sociodemographic variables such as age, gender, day of the week, and period of the year in which the accidents occurred were recorded. The analyses were performed by a gas chromatography-flame ionization method for alcohol and by a gas chromatography-mass spectrometry for amphetamines, cocaine, and cannabis.

RESULTS

The results showed that 44.8% (n = 175) of all cases were positive for alcohol and/or illicit drugs. The detection of alcohol and/or drugs was more frequent in young males, aged 17 to 34, whose samples were positive in 46.8% of cases. Small differences among drivers, passengers, and pedestrians were observed (drivers = 45.9%, passengers = 46.4%, and pedestrians = 45.6%). In general, the most prevalent drug was alcohol, with 141 positive cases (36.1%), followed by cocaine, with 47 positive cases (12%). Amphetamines and cannabis had positivity rates of 4.1 and 4.3%, with 16 and 17 positive cases, respectively. The combined use of alcohol and other drugs was found in 36 cases (9.2%). Crack cocaine use was observed in 27.7% of the positive cases for cocaine.

CONCLUSIONS

For the effective reduction of traffic accidents related to driving under influence of drugs (DUID), we suggest the intensification of enforcement actions against the use of alcohol by drivers, the definition of which illicit drugs should be surveyed, as well the cutoff values, the promotion of changing legislation to oblige drivers to provide samples for toxicological testing, and the establishment of public information programs and specific actions aimed at young drivers to promote behavioral changes.

Blood alcohol analysis alone versus comprehensive toxicological analysis - Systematic investigation of missed co-ingested other drugs in suspected alcohol-impaired drivers

Driving under the influence of alcohol and/or drugs (DUID) is a safety issue of increasing public concern. When a police officer has reasonable grounds to classify a driver as impaired, he may arrange for a blood sample to be taken. In many countries, alcohol analysis only is ordered if impairment is suspected to be exclusively due to alcohol while comprehensive toxicological screening will be performed if additional suspicion for other illegal drugs of abuse (DoA) or medicinal drugs is on hand. The aim of the present study was firstly to evaluate whether signs of impairment can be differentiated to be caused by alcohol alone or a combination of alcohol and other driving-impairing drugs and secondly to which extent additional drugs are missed in suspected alcohol-impaired drivers. A total of 293 DUID cases (negative n=41; alcohol positive only, n=131; alcohol+active drug positive, n=121) analyzed in 2015 in the Canton of Zurich were evaluated for their documented impairment symptoms by translating these into a severity score and comparing them applying principle component analysis (PCA). Additional 500 cases suspected for alcohol-impaired driving only were reanalyzed using comprehensive LC-MS/MS screening methods covering about 1500 compounds. Drugs detected were classified for severity of driving impairment using the classification system established in the DRUID study of the European Commission. As partly expected from the pharmacological and toxicological point of view, PCA analysis revealed no differences between signs of impairment caused by alcohol alone and those caused by alcohol plus at least one active drug. Breaking it down to different blood alcohol concentration ranges, only between 0.3 and 0.5g/kg trends could be observed in terms of more severe impairment for combined alcohol and drug intake. In the 500 blood samples retrospectively analyzed in this study, a total of 330 additional drugs could be detected; in some cases up to 9 co-ingested ones. In total, 37% of all cases were positive for additional drugs, thereby 15% of classic DoAs and further 9% of prescription drugs with a severe risk to cause driving impairment based on the DRUID classification system. A decision whether signs of impairment are related to alcohol alone or to the combination of alcohol and other drugs is impossible. Taking into consideration the high rate of missed drugs in DUI cases, police should think about increasing the number of DUID cases in countries were sanctioning differs between alcohol and alcohol plus drug impaired driving.

Underlying substance abuse problems in drunk drivers

OBJECTIVES

The aim of this study was to investigate polydrug use in drunk drivers.

METHODS

The experimental study was conducted on 2,072 drunk drivers undergoing a driving license reissue protocol at the Department of Legal Medicine of Padova University Hospital in the period between January 2011 and December 2012. The study protocol involved anamnesis, clinical examination, toxicological history, and toxicological analyses on multiple biological samples.

RESULTS

One thousand eight hundred seventy-seven subjects (90.6%) were assessed as fit to drive, and 195 (9.5%) were declared unfit. Among those unfit, 32 subjects (1.6%) were declared unfit due to recent use of an illicit drug (time span < 6 months), 23 (1.1%) spontaneously interrupted the protocol before its end, and 140 (6.8%) completed the assessment. Ineligibility to drive after completeness of the protocol was established in 1.2% of cases for alcohol disorders and in 5.7% of cases for illicit drug abuse; only one subject was included in both subgroups. Cocaine was the most widely used substance, followed by cannabis, opiates, and psychotropic pharmaceutical drugs.

CONCLUSIONS

The application of the protocol presented in this study allowed the identification of underlying polydrug use in drunk drivers. The study led to the identification of 6.8% unfit subjects on the basis of alcohol disorders and/or drug abuse, compared to 1.2% of identifiable unfitness if the protocol were limited to the mere assessment of alcohol consumption. The frequent association of alcohol and cocaine is different from other patterns of use in North Europe countries.

Trends in drug use among drivers killed in U.S. traffic crashes, 1999-2010

OBJECTIVE

Driving under the influence of drugs is a global traffic safety and public health concern. This trend analysis examines the changes in general drug usage other than alcohol, broad categories, and typical prescription and illegal drugs among drivers fatally injured in motor vehicle crashes from 1999 to 2010 in the U.S.

METHODS

Data from the Fatality Analysis Reporting System were analyzed from 1999 to 2010. Drug prevalence rates and prevalence ratios (PR) were determined comparing rates in 2009-2010 to 1999-2000 using a random effects model. Changes in general drug usage, broad categories, and representative prescription and illegal drugs including, methadone, oxycodone, hydrocodone, barbiturates, benzodiazepines, and cocaine, were explored.

RESULTS

Comparing 2009-2010 to 1999-2000, prevalence of drug usage increased 49% (PR=1.49; 95% confidence interval [CI] 1.42, 1.55). The largest increases in broad drug categories were narcotics (PR=2.73; 95% CI 2.41, 3.08), depressants (PR=2.01; 95% CI 1.80, 2.25), and cannabinoids (PR=1.99; 95% CI 1.84, 2.16). The PR were 6.37 (95% CI 5.07, 8.02) for hydrocodone/oxycodone, 4.29 (95% CI 2.88, 6.37) for methadone, and 2.27 (95% CI 2.00, 2.58) for benzodiazepines. Barbiturates declined in rate over the 12-year period (PR=0.53; 95% CI 0.37, 0.75). Cocaine use increased until 2005 then progressively declined, though the rate remained relatively unchanged (PR=0.94; 95% CI 0.84, 1.06).

CONCLUSIONS

While more drivers are being tested and found drug-positive, there is evidence that a shift from illegal to prescription drugs may be occurring among fatally injured drivers in the U.S. Driving under the influence of prescription drugs is a growing traffic concern.

The culpability of drivers killed in New Zealand road crashes and their use of alcohol and other drugs

Over a period of five years, blood samples were taken from 1046 drivers killed as a result of a motor vehicle crash on New Zealand roads. These were analysed for the presence of alcohol and a range of both illicit drugs and psychoactive medicinal drugs. Driver culpability was determined for all crashes. The control group of drug- and alcohol-free drivers comprised 52.2% of the study population. Drivers positive for psychoactive drugs were more likely to be culpable (odds ratio (OR) 3.5, confidence interval (CI) 95% 2.4-5.2) than the control group. Driver culpability exhibited the expected positive association with alcohol use (OR 13.7, 95% CI 4.3-44) and with combined alcohol and cannabis use (OR 6.9, 95% CI 3.0-16). There was only a weak positive association between cannabis use (with no other drug) and culpability (OR 1.3, CI 95% 0.8-2.3). Furthermore, the OR for drivers with blood tetrahydrocannabinol (THC) concentrations greater than 5 ng/mL was lower (OR 1.0, CI 95% 0.4-2.4) than drivers with blood THC concentrations less than 2 ng/mL (OR 3.1, CI 95% 0.9-10). This is inconsistent with results reported by other studies where a significant increase in crash risk was found with blood THC levels greater than 5 ng/mL. In this study, there were very few drivers who had used a single drug, other than cannabis or alcohol. Therefore, from this study, it is not possible to comment on any relationship between opioid, stimulant or sedative drug use and an increased risk of being killed in a crash for the drivers using these drugs. The results from a multivariate analysis indicate that driver gender, age group and licence status, (P=0.022, P=0.016, P=0.026, respectively), the type of vehicle being driven (P=0.013), the number of vehicles in the crash (P<0.001), the blood alcohol concentration of the driver (P<0.001) and the use of any drug other than alcohol and cannabis (P=0.044), are all independently associated with culpability.

Drug use among drivers who drank on alcohol outlets from Porto Alegre, Brazil

BACKGROUND

Driving under the influence of multiple substances is a public health concern, but there is little epidemiological data about their combined use and putative impact on driving in low and middle-income countries where traffic crashes have been clustering in recent years. The aim of this study is to estimate the prevalence of alcohol and drug use - as well as their associated factors - among drivers in the context of alcohol outlets (AOs).

METHODS

A probability three-stage sample survey was conducted in Porto Alegre, Brazil. Individuals who were leaving AO were screened, with the selection of 683 drivers who met the inclusion criteria. Drivers answered a structured interview, were breathalyzed, and had their saliva collected for drug screening. Prevalences were assessed using domain estimation and logistic regression models assessed covariates associated with substance use.

FINDINGS

Benzodiazepines 3.9% (SE 2.13) and cocaine 3.8% (SE 1.3) were the most frequently detected drugs in saliva. Among drivers who were going to drive, 11% had at least one drug identified by the saliva drug screening, 0.4% two, and 0.1% three drugs in addition to alcohol. In multivariable analyses, having a blood alcohol concentration (BAC)>0.06% was found to be associated with a 3.64 times (CI 95% 1.79-7.39) higher chance of drug detection, compared with interviewees with lower BACs.

CONCLUSIONS

To drive under the influence of multiple substances is likely to be found in this setting, highlighting an association between harmful patterns of consume of alcohol and the misuse of other substances.

Driving under the influence (DUI) among patients in opioid maintenance treatment (OMT): a registry-based national cohort study

AIMS

To investigate convictions for driving under the influence (DUI) before, during and after opioid maintenance treatment (OMT) and to examine factors associated with convictions for DUI during treatment.

DESIGN, SETTING AND PARTICIPANTS

Treatment data on all patients who started OMT in Norway between 1997 and 2003 (n = 3221) were cross-linked with national criminal records using unique person identifiers. Patients were followed over a 9-year period, before, during and in periods out of opioid maintenance treatment.

MEASUREMENTS

Data were formal charges leading to convictions recorded during four different time-periods: 3 years prior to application, waiting-list, in-treatment and in periods out of treatment.

FINDINGS

During OMT, convictions for DUI were reduced by almost 40% compared with pre-application levels. The conviction rate for DUI for males in the pre-application period was 9.59 per 100 person-years (PY) and for females, 3.44 per 100 PY. During OMT, rates of DUI convictions were reduced to 5.97 per 100 PY among men and to 1.09 per 100 PY among women. However, when estimating the effect of OMT on convictions for DUI, the interaction between gender and exposure to OMT was not statistically significant. Patients who remained in continuous treatment had fewer convictions for DUI during treatment compared with patients in discontinuous treatment. Compared with patients having no road traffic convictions during the pre-application period, patients with two or more pre-application convictions for DUI had higher odds [odds ratio (OR) = 3.69 (2.30-5.93)] for further convictions for DUI during OMT.

CONCLUSION

In Norway, patients receiving opioid maintenance treatment (OMT) have reduced convictions for driving under the influence (DUI) compared with their pre-treatment levels. Being male and having a previous history of several convictions for DUI were found to be important risk factors for convictions for DUI during OMT.

THCCOOH concentrations in whole blood: are they useful in discriminating occasional from heavy smokers?

Some forensic and clinical circumstances require knowledge of the frequency of drug use. Care of the patient, administrative, and legal consequences will be different if the subject is a regular or an occasional cannabis smoker. To this end, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) has been proposed as a criterion to help to distinguish between these two groups of users. However, to date this indicator has not been adequately assessed under experimental conditions. We carried out a controlled administration study of smoked cannabis with a placebo. Cannabinoid levels were determined in whole blood using tandem mass spectrometry. Significantly high differences in THCCOOH 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 THCCOOH 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 tested and found to be consistent with previously published experimental data. The decision threshold of 40 µg/L could be a cut-off for possible disqualification for driving while under the influence of cannabis. A further medical assessment and follow-up would be necessary for the reissuing of a driving license once abstinence from cannabis has been demonstrated. A THCCOOH level below 3 µg/L would indicate that no medical assessment is required.

Police custody following driving under the influence of cannabis: a prospective study

Traffic offences are a common cause of detention in police custody. We hypothesized that drug intoxication while driving could correspond to specific medical conditions of the detainees. Our objective was to evaluate medical features and addictive behaviours of suspected drug drivers and to collect data regarding assaults or injuries in these individuals. We conducted a prospective study (April 2010-December 2011) of suspected drug driving arrestees, who were compared to drink drivers or persons aged over 18 detained for other reasons. Data collected concerned persons' characteristics, reported assaults, and observed injuries. A total of 205 drivers were tested positive for drugs in blood, 116 were either positive for drugs in urine or saliva and negative in blood, or negative in urine. Cannabis-only users accounted for 201 of 205 drug drivers (98%). Suspected drug driving arrestees had good overall health rating. Drug drivers were younger than controls and requested more rarely medical examination (12% vs. 44%, P<0.0001). They were rarely involved in addiction treatment (3%) and reported assaults or presented traumatic injuries less often than drink drivers and controls (8% vs. 38% and 25%, P<0.0001). Drug drivers were less often alcohol abusers than controls. Their opinion on custody was better than that of controls and they were considered unconditionally fit for detention more frequently (99% vs. 77%, P<0.0001). We conclude that arrested drug drivers were young, healthy, and infrequently reported assaults or presented traumatic injuries, which does not put them in a high risk medical condition. Medical care could include brief interventions on addictive behaviours.

Cannabis effects on driving skills

BACKGROUND

Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, delays in sample collection, evaluating the inactive Δ(9)-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use.

CONTENT

We review and evaluate the current literature on cannabis' effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving.

SUMMARY

Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2-5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention, and include occasional and chronic daily cannabis smokers.

Weed or wheel! FMRI, behavioural, and toxicological investigations of how cannabis smoking affects skills necessary for driving

Marijuana is the most widely used illicit drug, however its effects on cognitive functions underlying safe driving remain mostly unexplored. Our goal was to evaluate the impact of cannabis on the driving ability of occasional smokers, by investigating changes in the brain network involved in a tracking task. The subject characteristics, the percentage of Δ(9)-Tetrahydrocannabinol in the joint, and the inhaled dose were in accordance with real-life conditions. Thirty-one male volunteers were enrolled in this study that includes clinical and toxicological aspects together with functional magnetic resonance imaging of the brain and measurements of psychomotor skills. The fMRI paradigm was based on a visuo-motor tracking task, alternating active tracking blocks with passive tracking viewing and rest condition. We show that cannabis smoking, even at low Δ(9)-Tetrahydrocannabinol blood concentrations, decreases psychomotor skills and alters the activity of the brain networks involved in cognition. The relative decrease of Blood Oxygen Level Dependent response (BOLD) after cannabis smoking in the anterior insula, dorsomedial thalamus, and striatum compared to placebo smoking suggests an alteration of the network involved in saliency detection. In addition, the decrease of BOLD response in the right superior parietal cortex and in the dorsolateral prefrontal cortex indicates the involvement of the Control Executive network known to operate once the saliencies are identified. Furthermore, cannabis increases activity in the rostral anterior cingulate cortex and ventromedial prefrontal cortices, suggesting an increase in self-oriented mental activity. Subjects are more attracted by intrapersonal stimuli ("self") and fail to attend to task performance, leading to an insufficient allocation of task-oriented resources and to sub-optimal performance. These effects correlate with the subjective feeling of confusion rather than with the blood level of Δ(9)-Tetrahydrocannabinol. These findings bolster the zero-tolerance policy adopted in several countries that prohibits the presence of any amount of drugs in blood while driving.

Drivers under the influence of drugs of abuse: quantification of cocaine and impaired driving

In recent years, the interest in oral fluid as a biological matrix has significantly increased, particularly for detecting driving under the influence of drugs. In this study, the concentration of cocaine and its relationship with clinical symptoms in drivers suspected of driving under the influence of drugs was evaluated. A total of 154 samples of oral fluid, which tested positive for cocaine in previous immunoassay screening, Cozart Drug Detector System, were confirmed using gas chromatography/mass spectrometry method. In Catalonia, during 2007-2010, there were 1791 samples positive for cocaine among a total of 3468 samples taken from drivers who tested positive for any drug of abuse. The evaluation of clinical symptoms was through a questionnaire that was filled in by the police officers who collected the samples. The mean concentration of cocaine was 4.11 mg/l and median concentration was 0.38 mg/l (range 0.01-345.64 mg/l). Clinical impairment symptoms such as motor coordination, walking, speech, mood and state of pupils were not significant. The testing of oral fluids presents fewer ethical problems than blood or urine.

Comparison of drug concentrations measured in roadside surveys and in seriously injured drivers in Belgium

The objective of this paper is to compare concentrations of alcohol, illicit, and medicinal drugs in seriously injured drivers and drivers selected randomly at the roadside. Blood samples were analyzed for alcohol, 17 medicinal drugs and 8 illicit psychoactive substances and/or their metabolites by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography mass spectrometry (GC-MS) in injured drivers admitted to the emergency departments of five hospitals in Belgium between January 2008 and May 2010 and in drivers randomly selected between January 2008 and September 2009. Three hundred and seventy-seven seriously injured drivers and 2750 roadside respondents were selected. In the roadside survey, out of the 203 concentrations above DRUID (Driving Under the Influence of Drugs, Alcohol and Medicines) cut-offs for medicinal drugs, 51% were in the therapeutic range, 46% infratherapeutic, and 2.5% supratherapeutic. In the seriously injured drivers, out of the 78 concentrations above DRUID cut-offs for medicinal drugs, these percentages were respectively 63%, 33%, and 4%. Significant differences were found in the distribution of concentrations for opioids, benzodiazepines, and Z-drugs. For the latter, while in the seriously injured drivers study most concentrations were therapeutic, in the roadside survey most were infratherapeutic. The opposite was observed for the opioids. Eight and 41% of the roadside respondents and injured drivers, respectively, had an alcohol concentration above 0.1 g/L, with higher concentrations found in the injured drivers. For illicit drugs, significant differences were found for amphetamine and cocaine, for which respectively lower and higher concentrations were observed in the blood samples taken in the roadside survey.

The incidence of alcohol and other drugs in drivers killed in New Zealand road crashes 2004-2009

Alcohol is a drug known to impair the ability to drive safely and is acknowledged as a major factor in New Zealand road crashes. However, the use of other impairing drugs by New Zealand drivers is largely unknown. This paper reports the prevalence of drug use by drivers killed on New Zealand roads. As this is a biased population sample the results can only indicate possible drug use in the wider driving population. Blood samples taken from 1046 deceased drivers were analysed for the presence of alcohol and a range of both illicit drugs and psychoactive medicinal drugs. Five hundred and forty-six (52%) of these drivers had not used alcohol or other potentially impairing drugs. Five hundred (48%) had alcohol and/or other drugs in their blood that may have impaired their ability to drive safely. Of these 500 drivers, 135 had used alcohol alone, 96 had used cannabis alone and 142 had used a combination of alcohol and cannabis, but no other drug. Alcohol concentrations in 351 drivers who had drunk alcohol ranged from 5 to 354 mg per 100 mL (mean 152 mg/100 mL). Levels of tetrahydrocannabinol (THC) in the blood of the 314 drivers who had used cannabis ranged from approximately 0.1 ng/mL to 44 ng/mL (mean 5.6 ng/mL). There were 127 drivers who had used some other combination of drugs, many still including alcohol and/or cannabis. Only 29 of the 500 drivers who had used a drug, had not used either cannabis or alcohol and 240 (48%) of the 500 drivers had used more than one potentially impairing drug.

Driving under the influence of amphetamine-like drugs

Scientific opinions differ whether the use of stimulants causes deterioration in driving skills. In 1857 of 8709 cases of driving under the influence of drugs, amphetamine-like drugs (amphetamine, methamphetamine, and methylendioxyamphetamine) were present either alone or together with other licit or illicit drugs. In 338 cases, amphetamines were the only psychoactive substance group in plasma at mean, median, and highest concentrations of 0.18, 0.12, and 1.05 mg/L, respectively. A widespread opinion is that after the consumption of amphetamines, centrally stimulating effects with corresponding consequences on safe driving are expected. In contrast, many cases were observed that rather suggested an influence of centrally sedating substances when considering the psycho-physical conditions. Relations between concentration and effect could not be established. The apparent sedation is probably the consequence of sleep deprivation during an amphetamine binge and the after-effects of the drug.

The effect of d,l-methamphetamine on simulated driving performance

RATIONALE

Illicit drugs such as methamphetamine are commonly abused drugs that have also been observed to be prevalent in drivers injured in road accidents. The exact effect of methamphetamine or its specific isomers on driving and driving behaviour have yet to be thoroughly investigated.

METHODS

Twenty healthy recreational illicit stimulant users (ten males, ten females), aged between 21 and 34 years (mean = 24.3 years, SD = 3.4 years), attended two testing sessions involving oral consumption of 0.42 mg/kg d,l-methamphetamine or a matching placebo. The drug administration was counterbalanced, double-blind, and medically supervised. At each session, driving performance was assessed 2.5 h post-drug administration.

RESULTS

Mean blood and saliva d,l-methamphetamine concentrations of approximately 90 and 400 ng/ml, respectively, at 2 h and 95 and 475 ng/ml at 3 h were observed. These levels of d,l-methamphetamine were found not to significantly impair, or improve, driving performance at the 2.5-h post-drug administration time point.

CONCLUSIONS

The findings of this study illustrate that d,l-methamphetamine has no significant effect on simulated driving performance.