Journal of analytical toxicology
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The misuse of designer benzodiazepines, as an alternative to prescription benzodiazepines and for drug-facilitated sexual assaults, has emerged as a growing threat, due in part to the ease of purchasing these drugs on the internet at low prices. Causing concern for safety is the lack of dosage information resulting in users self-medicating, often leading to unintended overdoses, coma or death at higher doses. With limited published data regarding the quantification of designer benzodiazepines in forensic cases, a method was validated for the determination of 13 designer benzodiazepines in postmortem blood, to add to the in-house method that already included a limited number of common designer benzodiazepines. ⋯ Recovery ranged from 35 to 90%, where only two compounds were <50%. Other parameters tested included carryover, stability, interference and dilution integrity, which all yielded acceptable results. With the application of this method to blood specimens from the New York City Office of Chief Medical Examiner, this validated method proved to be simple, reproducible, sensitive and robust.
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Toxicology laboratories commonly employ immunoassay methodologies to perform an initial drug screen on urine specimens to direct confirmatory testing. Due to limitations of immunoassay testing and the need to screen for a broader range of drugs with lower limits of detection at a lower cost, mass spectrometry screening techniques have gained favor in the toxicology field. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) urine screening panel was developed and validated for 52 drugs and metabolites. ⋯ Comparing the toxicology results of forensic urine specimens demonstrated that by only using ELISA, the laboratory was unable to detect benzoylecgonine in 26%, lorazepam in 33% and oxymorphone in 60% of the positive specimens. Additional analytes detected using the LC-MS-MS method were zolpidem and/or metabolite, gabapentin, tramadol and metabolite, methadone and metabolite, meprobamate and phentermine. The results of the validation, the toxicological result comparison and the cost comparison showed that the LC-MS-MS screening method is a simple, sensitive and cost-effective alternative to ELISA screening methods for urine specimens.
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This study demonstrates the validation of a semi-quantitative method for the rapid screening of whole blood and urine specimens using clonazepam as the target molecule for the Neogen® Benzodiazepine kit. Decision points were validated at 10.0 ng/mL for whole blood and 25.0 ng/mL for urine. The validation design was based on the Scientific Working Group for Forensic Toxicology (SWGTOX) Standard Practices for Method Validation and included the evaluation of sensitivity, precision, specificity, carryover, hook effect, drift, ruggedness/robustness and a case sample evaluation. ⋯ However, both the blood and urine matrix did meet the proposed revision of the SWGTOX requirements for determining a valid decision point promulgated by the American Academy of Forensic Sciences Standards Board and the assay was reliably able to detect benzodiazepines without interference from matrix components or other compounds routinely detected in authentic case samples. Case sample results were comparable with those obtained when the samples were initially screened using oxazepam as the target molecule. The Neogen® Benzodiazepine kit using clonazepam as the target molecule exhibited cross-reactivity for 29 different benzodiazepines and demonstrated excellent precision and sensitivity in both whole blood and urine, making it an efficient and reliable method to screen for benzodiazepines, even though the validation did not fulfill current SWGTOX requirements for a valid decision point.
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Currently, an unprecedented number of individuals can legally access cannabis. Vaporization is increasingly popular as a method to self-administer cannabis, partly due to perception of reduced harm compared with smoking. Few controlled laboratory studies of cannabis have used vaporization as a delivery method or evaluated the acute effects of cannabis among infrequent cannabis users. ⋯ Blood and/or oral fluid cannabinoid concentrations were weakly to moderately correlated with pharmacodynamic outcomes. Cannabis pharmacokinetics vary by method of inhalation and biological matrix being tested. Vaporization appears to be a more efficient method of delivery compared with smoking.
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Case Reports
A Liquid-Chromatography High-Resolution Mass Spectrometry Method for Non-FDA Approved Benzodiazepines.
Benzodiazepines (BZDs) are widely used for treatment of anxiety and insomnia, however, this class of drugs is also commonly abused. Many different BZDs and analogs have been produced that are not FDA-approved. We tested 15 of these with the ThermoFisher CEDIA® BZD-immunoassay. ⋯ The limit of detection for most compounds ranged from 1 to 50 ng/mL, with mostly positive matrix effects observed in urine and negative matrix effects in serum. In a clinical research case, clonazolam and etizolam were detected in serum at 10.2 and 281 ng/mL, with an apparent elimination half-life of 3.6 and 4.8 hours, respectively. Although we did not detect non-FDA approved BZDs in 211 urine samples that were previously determined to be BZD-positive by immunoassay, abuse of these drugs is on the rise and clinical and forensic toxicology laboratories should consider developing methods to detect them.