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Two challenges in detecting γ-hydroxybutyric acid (GHB) intake are its endogenous presence and in vitro production after sampling. This study developed an LC-MS/MS method for selective GHB determination in human antemortem blood, urine, and oral fluid at endogenous concentrations. Furthermore, the stability of GHB in blood samples and its endogenous concentrations in samples taken under controlled circumstances were investigated. Samples were extracted in methanol/acetonitrile and processed by anion exchange solid-phase extraction. GHB was separated from structural isomers using a reversed-phase LC column with anion properties. The validated limit of quantification was 0.005 µg/mL in blood and 0.010 µg/mL in urine and oral fluid, at which the relative reproducibility standard deviation and bias were <15 %. The mean extraction recovery was ≥90 %. The average GHB concentration increased by 1.2 µg/mL in fluoride/citrate- preserved blood after 28 days of storage at 4°C; however, in fluoride/oxalate (FX)-preserved blood, the mean concentration increased by only 0.055 µg/mL. No change was observed at -20°C. In 105 randomly selected samples of FX-preserved blood collected for forensic antemortem toxicological analysis, all concentrations were <0.066 µg/mL, even after long-term storage at -20°C. In blood, urine, and oral fluid samples from a clinical study of GHB intake, endogenous baseline levels from 30 participants ranged from 0.0069-0.050, 0.024-0.38, and 0.034-0.93 µg/mL, respectively. These results demonstrate that the current cut-off level of 5 µg/mL for discriminating between endogenous and exogenous GHB in antemortem blood could be considerably lower for FX-preserved blood stored at -20°C., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

For prospective investigation of drugs and metabolites in archaeological and contemporary dental calculus, a sensitive, broadly applicable ultra-high-performance liquid chromatography-tandem mass spectrometry method using pneumatically assisted electrospray ionisation (UHPLC-ESI-MS/MS) was developed. The dental calculus was treated with citric acid and the dissolution extracts were cleaned using weak and strong polymeric cation-exchange sorbents. The method was validated on hydroxyapatite for the analysis of 67 drugs and metabolites. Typically, the lower limits of quantification were in the range of 0.01-0.05ng for the sample mass extracted. The general applicability of the method was tested using dental calculus material sampled from 10 corpses undergoing forensic autopsy. The calculus material was washed several times before dissolution to remove residual substances originating from saliva, gingival crevicular fluid and blood. The wash extracts and the calculus samples (cleaned calculus material) were analysed using the same instrumental conditions. The dry mass of the calculus samples ranged from 1 to 10mg. The total number of drug detections was 131 in the dental calculus samples and 117 in the whole blood samples. From the analyses of the wash extracts and calculus samples, it was proven that drug residues were trapped in the interior of the calculus material. In 82 of the drug detections, the drug concentrations were higher in the dental calculus than in the blood. Among substances detected in the dental calculus but not in the blood were cocaine, heroin, 6-MAM and THCA-A., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Femoral blood concentrations are usually used in postmortem toxicology to assess possible toxic effects of drugs. This includes QT-prolongation and other cardiac dysrhythmia, which could have been the cause of death. However, blood concentration is only a surrogate for the active site concentration, and therefore cardiac tissue concentration may provide a more accurate toxicological interpretation. Thus, cardiac tissue and femoral and cardiac blood concentrations were examined for eight frequently used QT-prolonging drugs (QTD) and their metabolites in a mentally ill population. In total, 180 cases were included from the Danish autopsy-based forensic study SURVIVE. The concentrations were analyzed using ultra-performance liquid chromatography coupled with tandem mass spectrometry utilizing stable isotopically labeled internal standards. The results showed that the cardiac tissue concentrations were significantly higher compared to femoral and cardiac blood concentrations, with two exceptions. The median cardiac tissue-to-femoral blood concentration ratio (Kb) ranged from 2.2 (venlafaxine) to 15 (nortriptyline). The inter-individual fold difference between the minimum and maximum Kb ranged from 2.6-fold (Z-hydroxynortriptyline) to 61 (venlafaxine). For 12 compounds, postmortem redistribution appeared to be minimal, whereas four compounds displayed some degree of postmortem redistribution. Citalopram and quetiapine were selected for in-depth analysis of the relation between the toxicological interpretation and femoral blood/cardiac tissue concentrations. Within this dataset, citalopram displayed a wide overlap in cardiac tissue concentrations (~50%) between non-toxic and toxic citalopram cases, as estimated from femoral blood concentrations. In contrast, quetiapine displayed no overlap in cardiac tissue concentrations between non-toxic and toxic quetiapine cases based on femoral blood concentrations. The implication of the citalopram finding is that possible intoxications can be overlooked when only considering femoral blood concentrations. Based on the present findings, non-toxic cardiac tissue 10th-90th percentile concentration ranges were estimated for citalopram (0.93-4.4 mg/kg) and quetiapine (0.0073-0.60 mg/kg).

The illicit drug 3,4-methylenedioxymethamphetamine (MDMA) has profound physiological cerebral, cardiac, and hepatic effects that are reflected in the blood. Screening of blood for MDMA and other narcotics are routinely performed in forensics analysis using ultra-performance liquid chromatography with high-resolution time-of-flight mass spectrometry (UPLC-HR-TOFMS). The aim of this study was to investigate whether such UPLC-HR-TOFMS data collected over a two-year period could be used for untargeted metabolomics to determine MDMA metabolites as well as endogenous changes related to drug response and toxicology. Whole blood samples from living Danish drivers' positive for MDMA in different concentrations were compared to negative control samples using various statistical methods. The untargeted identification of known MDMA metabolites was used to validate the methods. The results further revealed changes of several acylcarnitines, adenosine monophosphate, adenosine, inosine, thiomorpholine 3-carboxylate, tryptophan, S-adenosyl-l-homocysteine (SAH), and lysophospatidylcholine (lysoPC) species in response to MDMA. These endogenous metabolites could be implicated in an increased energy demand and mechanisms related to the serotonergic syndrome as well as drug induced neurotoxicity. The findings showed that it was possible to extract meaningful results from retrospective UPLC-HR-TOFMS screening data for metabolic profiling in relation to drug metabolism, endogenous physiological effects, and toxicology.

Vigabatrin, pregabalin, gabapentin and baclofen are γ-aminobutyric acid analogs that are used in the treatment of epileptic seizures (vigabatrin, pregabalin and gabapentin) and spasticity (baclofen). The intake of these drugs may induce adverse reactions and impair the ability of an individual to drive a vehicle. There have also been reports of cases of intoxication and fatalities from overdoses. For rapid and accurate quantification of these drugs in forensic cases, an ultraperformance liquid chromatography tandem mass spectrometry method using pneumatically assisted electrospray ionization has been developed. The technique has been validated on both ante- and postmortem human whole blood. The protein in the blood samples was removed by the addition of a mixture of methanol and acetonitrile, and the extract was ultrafiltered and diluted with acetonitrile. The separation was performed by hydrophilic interaction liquid chromatography. Calibration of the system was achieved through use of matrix-matched calibrants combined with isotope dilution. The lower limits of quantification were 0.02-0.04 mg/L, and the relative intra-laboratory reproducibility standard deviations were <4 and 8% at concentrations of 10 and 1 mg/L, respectively. The mean true recoveries were >89%. The trueness expressed as the relative bias of the test results was within ±7% at concentrations of 1-40 mg/L for vigabatrin, pregabalin and gabapentin and of 0.1-4 mg/L for baclofen.

Information regarding deaths caused by poisoning or adverse effects of medication in Danish persons not using illicit narcotic drugs (PNUIDs) is sparse. To characterize aetiology, demographics, and death scene, we reviewed all legal autopsies performed at Aarhus University from 2017 to 2019 and isolated 96 deaths caused by medications in PNUIDs. Suicides caused by medication overdose accounted for 38%. Opioids and psychotropic medications were the main cause of death in 48% and 35% of the 96 cases, respectively. Morphine, tramadol, and quetiapine were the most commonly involved individual medications. A single medication caused death in 50% of cases, and multiple substances were involved in 50%. The median total number [interquartile range] of detected medications was 5 [4–6], with a higher number in females (5 [4–7]) than males (4 [2–5]), p = 0.009. Median age was 51 [42.5–61.5] years, and 57% were female. Scene of death most frequently involved a body on a bed or couch in the decedent's own home (72%). In conclusion, opioids and psychotropic medications dominated by morphine, tramadol and quetiapine most frequently caused medication‐related deaths in PNUIDs. Monitoring this type of death may yield important knowledge to direct prophylactic initiatives regarding medication use and prescription. [ABSTRACT FROM AUTHOR]