[Cannabis and driving: the situation in Europe]

Toxicological Investigation of Drug-Related Cases in Greece: Interpretation of Analytical Findings

The process of toxicological analysis of postmortem specimens can reveal some special difficulty compared to the clinically derived specimens. Many drugs are not stable and the chemical changes that occur in the specimens, due to the hydrolysis processing, the time passed, the drug metabolism, and matrix effect, even when the postmortem interval is short, may affect the interpretation of the toxicological results. This interpretation may be critical, not only to the thorough investigation of different kind of forensic cases, but also to clinical or other cases as it provides very significant challenges to the scientists. This article reviews (a) particular toxicological issues associated with some toxic substances responsible for common lethal or nonlethal poisonings, such as opiates, cannabis, and cocaine and the vast number of factors that affect drug concentration; and (b) focuses on toxicological issues associated with the analytical findings of certain postmortem specimens. The toxic substances cited in the present paper are the most commonly found in forensic cases in Greece. The investigation of these drug-related deaths has revealed that heroin, alone or in combination with other psychoactive substances, such as cannabis and cocaine, is the main drug involved in these deaths.

The cannabinoid system and visual processing: a review on experimental findings and clinical presumptions

Cannabis is one of the most prevalent drugs used worldwide. Regular cannabis use is associated with impairments in highly integrative cognitive functions such as memory, attention and executive functions. To date, the cerebral mechanisms of these deficits are still poorly understood. Studying the processing of visual information may offer an innovative and relevant approach to evaluate the cerebral impact of exogenous cannabinoids on the human brain. Furthermore, this knowledge is required to understand the impact of cannabis intake in everyday life, and especially in car drivers. Here we review the role of the endocannabinoids in the functioning of the visual system and the potential involvement of cannabis use in visual dysfunctions. This review describes the presence of the endocannabinoids in the critical stages of visual information processing, and their role in the modulation of visual neurotransmission and visual synaptic plasticity, thereby enabling them to alter the transmission of the visual signal. We also review several induced visual changes, together with experimental dysfunctions reported in cannabis users. In the discussion, we consider these results in relation to the existing literature. We argue for more involvement of public health research in the study of visual function in cannabis users, especially because cannabis use is implicated in driving impairments.

Predictors of driving after alcohol and drug use among adolescents in Valencia (Spain)

BACKGROUND

Driving under the influence of alcohol and drugs has been identified as a risk factor for road traffic crashes. We have assessed the prevalence and predictor factors for driving after alcohol and drug use by adolescents.

METHODS

A cross-sectional survey involving 11,239 students aged 14-18 years from 252 private and public schools in the Valencia region of Spain was conducted. The prevalence and predictors of driving after alcohol use, alcohol and drug use, or drug use during the previous 6 months were measured.

RESULTS

Of the students who reported driving (20%), 45.1% indicated driving after alcohol and drug use. The consumption of various drugs was higher among students who drove a vehicle compared with those who did not. The likelihood of driving after consuming alcohol, or alcohol and drugs, increased in line with the number of standard drink units per week, reports of any lifetime alcohol- or drug-related problems, and poor family relationship. In addition, masculine gender and early alcohol use increased the likelihood of driving after consuming alcohol.

CONCLUSIONS

Driving after alcohol and drug use is quite prevalent among adolescents in the Valencia region of Spain. There is a need for implementation of targeted policies for adolescents. This should focus on education and information on alcohol/drug use and driving.

Conventional and alternative matrices for driving under the influence of cannabis: recent progress and remaining challenges

In the past decade much research concerning the impact of cannabis use on road safety has been conducted. More specifically, studies on effects of cannabis smoking on driving performance, as well as epidemiological studies and cannabis-detection techniques have been published. As a result, several countries have adopted driving under the influence of drugs (DUID) legislations, with varying approaches worldwide. A wide variety of bodily fluids have been utilized to determine the presence of cannabis. Urine and blood are the most widely used matrices for DUID legislations. However, more and more publications focus on the usability of oral fluid testing for this purpose. Each matrix provides different information about time and extent of use and likelihood of impairment. This review will focus on the practical aspects of implying a DUID legislation. The pros and cons of the different biological matrices used for Δ9-tetrahydrocannabinol screening and quantification will be discussed. In addition, a literature overview concerning (roadside) cannabinoid detection, as well as laboratory confirmation techniques is given. Finally, we will discuss important issues influencing interpretation of these data, such as oral fluid collection, choice of cut-offs, stability and proficiency testing.

Simultaneous quantification of cannabinoids and metabolites in oral fluid by two-dimensional gas chromatography mass spectrometry

Development and validation of a method for simultaneous identification and quantification of Delta9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), and metabolites 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THCCOOH) in oral fluid. Simultaneous analysis was problematic due to different physicochemical characteristics and concentration ranges. Neutral analytes, such as THC and CBD, are present in ng/mL, rather than pg/mL concentrations, as observed for the acidic THCCOOH biomarker in oral fluid. THCCOOH is not present in cannabis smoke, definitively differentiating cannabis use from passive smoke exposure. THC, 11-OH-THC, THCCOOH, CBD, and CBN quantification was achieved in a single oral fluid specimen collected with the Quantisal device. One mL oral fluid/buffer solution (0.25 mL oral fluid and 0.75 mL buffer) was applied to conditioned CEREX Polycrom THC solid-phase extraction (SPE) columns. After washing, THC, 11-OH-THC, CBD, and CBN were eluted with hexane/acetone/ethyl acetate (60:30:20, v/v/v), derivatized with N,O-bis-(trimethylsilyl)trifluoroacetamide and quantified by two-dimensional gas chromatography electron ionization mass spectrometry (2D-GCMS) with cold trapping. Acidic THCCOOH was separately eluted with hexane/ethyl acetate/acetic acid (75:25:2.5, v/v/v), derivatized with trifluoroacetic anhydride and hexafluoroisopropanol, and quantified by the more sensitive 2D-GCMS-electron capture negative chemical ionization (NCI-MS). Linearity was 0.5-50 ng/mL for THC, 11-OH-THC, CBD and 1-50 ng/mL for CBN. The linear dynamic range for THCCOOH was 7.5-500 pg/mL. Intra- and inter-assay imprecision as percent RSD at three concentrations across the linear dynamic range were 0.3-6.6%. Analytical recovery was within 13.8% of target. This new SPE 2D-GCMS assay achieved efficient quantification of five cannabinoids in oral fluid, including pg/mL concentrations of THCCOOH by combining differential elution, 2D-GCMS with electron ionization and negative chemical ionization. This method will be applied to quantification of cannabinoids in oral fluid specimens from individuals participating in controlled cannabis and Sativex (50% THC and 50% CBD) administration studies, and during cannabis withdrawal.

[Illicit drugs, medications and traffic accidents]

The European Union (EU) has 25 member-states and 455 million inhabitants. Statistics on traffic accidents in the EU show that more than 45,000 people are killed annually, including 5200 in France. At the same time, nearly two million persons in the EU require medical treatment for traffic-accident-related injuries, including 109,000 in France. In addition, traffic accidents are the major cause of death of those individuals aged 15 to 24 years. One third of the EU inhabitants will be hospitalized during their life due to a traffic accident with a cost over 160 billion euro (2-3% of the Gross Domestic Product). An important contributing factor to crashes is the use of alcohol and/or illicit drugs or medication when driving, as they exert negative effects on cognition and psychomotor functions. For illicit drugs, abuse of cannabis with or without alcohol is a major concern for the EU. In fact, three million Europeans use cannabis daily and 80% of them drive after use. A number of French studies since 1999 have underlined the high prevalence of cannabis found in the blood of injured or killed drivers. From medical or judicial observations, it is clear that cannabis use increases the risk of traffic accidents. Many groups outside Europe have also shown the association between drug abuse and crashes. The number of casualties related to certain medicines, especially benzodiazepines remains at a high level, particularly in the elderly. In many countries the prevalence of medicinal drugs associated with car accidents is higher than with cannabis. Annex III of the European Union Council Directive of July the 29th 1991 in fact states that a driving license should not be issued to or renewed for applicants or drivers who are dependent on psychotropic substances or use them regularly. Recently, France has categorized the medicinal drugs available in the country by using three pictograms: level one yellow, "be careful"; level two orange, "be very careful"; level three red, "don't drive". It is an important campaign that increases awareness among the public and the medical professionals about the potential dangerous effects of medicinal drugs when driving. The EU objective of reducing the number of fatalities to 25,000 by 2010 will require strengthening measures against the use of alcohol, illicit and medicinal drugs by not well-informed drivers. It is not only a really great challenge, but also a significant investment towards improving public health in France as well as in Europe.