Driving under the influence of cocaine: Quantitative determination of basic drugs in oral fluid obtained during roadside controls and a controlled study with cocaine users

High-Affinity Aptamers for In Vitro and In Vivo Cocaine Sensing

The ability to quantify cocaine in biological fluids is crucial for both the diagnosis of intoxication and overdose in the clinic as well as investigation of the drug's pharmacological and toxicological effects in the laboratory. To this end, we have performed high-stringency in vitro selection to generate DNA aptamers that bind cocaine with nanomolar affinity and clinically relevant specificity, thus representing a dramatic improvement over the current-generation, micromolar-affinity, low-specificity cocaine aptamers. Using these novel aptamers, we then developed two sensors for cocaine detection. The first, an in vitro fluorescent sensor, successfully detects cocaine at clinically relevant levels in 50% human serum without responding significantly to other drugs of abuse, endogenous substances, or a diverse range of therapeutic agents. The second, an electrochemical aptamer-based sensor, supports the real-time, seconds-resolved measurement of cocaine concentrations in vivo in the circulation of live animals. We believe the aptamers and sensors developed here could prove valuable for both point-of-care and on-site clinical cocaine detection as well as fundamental studies of cocaine neuropharmacology.

Combined Use of Flubromazepam and Stimulants: Blood and Oral Fluid Concentrations and Impact on Driving Ability

"Designer" benzodiazepines (DBZDs) are becoming increasingly available in Europe, with the European Monitoring Centre of Drugs and Drug Addiction currently monitoring ∼30 new benzodiazepines. The following driving under the influence of drug (DUID) case describes the oral fluid (OF) and blood concentrations, as well as the observed effects after the combined use of stimulants and flubromazepam. Both OF, collected via the Intercept i2 collector (Immunalysis, Pomona, CA, USA), and blood (collected in containers with various stabilizers) were screened using a liquid chromatographic (LC) time-of-flight (TOF) mass spectrometric (MS-MS) method. In addition, various LC-MS-MS methods in multi-reaction monitoring mode were applied for confirmation and quantification. The OF and blood samples were taken 2 h 25 min and 9 h 19 min after the accident, respectively. OF contained 789 ng/mL amphetamine, 5,173 ng/mL MDMA, 168 ng/mL benzoylecgonine, 492 ng/mL cocaine, 134 ng/mL 4-methylmethcathinone (4-MMC) and traces of flubromazepam (less than limit of quantification (LLOQ); 2 ng/mL). The sodium-fluoride blood samples contained 19 ng/mL amphetamine, 284 ng/mL MDMA, 20 ng/mL MDA, 38 ng/mL benzoylecgonine, 4 ng/mL methylecgonine, 161 ng/mL flubromazepam and traces of 4-MMC (<LLOQ; 2.5 ng/mL). The driver was observed to have an irregular speed driving pattern and could not keep his lane. He demonstrated the following effects after the accident: bloodshot eyes, red face, sweating, fatigue, disorientation in time and space and mental confusion. Even 24 h after the accident, the driver was confused, disoriented, had red spots on his face and could not keep his balance. The effects of flubromazepam combined with several stimulants are demonstrated. Moreover, this case illustrates well the pros and cons of the different biological matrices applied in a DUID context. Differences between the biological matrices are not only observed concerning the ease/practicality of (on-site) collection, but also in the final drug detectability due to the large variations in OF/blood drug concentration ratios and metabolism/elimination rates as a result of the different chemical entities of the compounds.

Cocaine in Different Matrices: Recent Updates on Pretreatment and Detection Techniques

Cocaine abuse has attracted increased attention in the recent past since it can cause addiction and great harm to the normal human body. Due to cocaine exists in various complex matrices, the detection of it in different matrices is helpful to prevent abuse. It is thus imperative to establish efficient and accurate methods for pretreatment and detection of cocaine in different samples. The present study provides a summary of the research progress of cocaine pretreatment methods (such as different microextraction methods, QuEChERS, and solid phase extraction based on novel extraction materials) and detection approaches (such as liquid chromatography coupled with different detectors, gas chromatography and related techniques, capillary electrophoresis and sensors). A comparison of the pros and cons of different pretreatment and detection methods is presented. The findings of this study will provide a reference for selection of the most suitable cocaine pretreatment and detection techniques.

Positivity to Cocaine and/or Benzoylecgonine in Confirmation Analyses for On-Road Tests in Spain

We are using real-life data in order to determine the prevalence of driving with the presence of cocaine and/or benzoylecgonine (BZE), their concentrations, and their use in combination with other drugs. This study assessed data on Spanish drivers with confirmed drug-positive results recorded by the Spanish National Traffic Agency from 2011-2016. Frequencies of positivity for cocaine and/or BZE and concentration of such substances were obtained. Comparisons and univariate and multivariate regression analyses were performed. Drivers who tested positive for cocaine and/or BZE accounted for 48.59% of the total positive results for drugs. In positive cases for both cocaine and BZE, other substances were detected in 81.74%: delta-9-tetrahydrocannabinol (THC) (68.19%), opioids (20.78%) and amphetamine-like substances (16.76%). In the multivariate logistic regression analysis, the frequency of cocaine and/or BZE positive cases decreased with age (OR:0.97) and were less likely among women (OR:0.63). Concentrations (ng/mL) of cocaine (249.30) and BZE (137.90) were higher when both substances were detected together than when detected alone. Positivity to cocaine represented an important proportion among Spanish drivers who tested positive for drugs, and polysubstance use was especially observed in more than 8 out of 10 positive cases for cocaine and/or BZE.

Interpol review of toxicology 2016-2019

This review paper covers the forensic-relevant literature in toxicology from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20.Papers%202019.pdf.

Oral Fluid Drug Testing: Analytical Approaches, Issues and Interpretation of Results

With advances in analytical technology and new research informing result interpretation, oral fluid (OF) testing has gained acceptance over the past decades as an alternative biological matrix for detecting drugs in forensic and clinical settings. OF testing offers simple, rapid, non-invasive, observed specimen collection. This article offers a review of the scientific literature covering analytical methods and interpretation published over the past two decades for amphetamines, cannabis, cocaine, opioids, and benzodiazepines. Several analytical methods have been published for individual drug classes and, increasingly, for multiple drug classes. The method of OF collection can have a significant impact on the resultant drug concentration. Drug concentrations for amphetamines, cannabis, cocaine, opioids, and benzodiazepines are reviewed in the context of the dosing condition and the collection method. Time of last detection is evaluated against several agencies' cutoffs, including the proposed Substance Abuse and Mental Health Services Administration, European Workplace Drug Testing Society and Driving Under the Influence of Drugs, Alcohol and Medicines cutoffs. A significant correlation was frequently observed between matrices (i.e., between OF and plasma or blood concentrations); however, high intra-subject and inter-subject variability precludes prediction of blood concentrations from OF concentrations. This article will assist individuals in understanding the relative merits and limitations of various methods of OF collection, analysis and interpretation.