Seized drug reporting of NPS helps to guide regional toxicological practice: A 17 month review between 2022 and 2023.

Novel psychoactive substances (NPS) are everchanging and plague forensic laboratories who must identify an unending variety of emerging substances and evolve current methodologies to detect these substances. Identifying potential regional NPS targets and timely examining trends in seized drug data could help mitigate the burden laboratories face. Over 17 months, NPS seized drug data were processed and categorized from three laboratories located across the United States to determine any NPS regional similarities and prevalent NPS drug categories: the South Carolina Law Enforcement Division (SLED), the Sedgwick County Regional Forensic Science Center (SCRFSC), and the Orange County Crime Laboratory (OCCL). Seized drug materials, including pills, powders, and plant material, were primarily analyzed for NPS via gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy. From June 2022 to October 2023, 1940 NPS seized drug identifications were reported by these laboratories with 63 different NPS reported. Novel synthetic opioids (NSO) were the most prevalent NPS class across all three laboratories (55%), with fluorofentanyl accounting for 74% of NSO identifications. This is unsurprising given the fentanyl epidemic in the United States. Furthermore, these data highlighted varying regional NPS seized drug trends: eutylone, a synthetic cathinone, was one of the most frequently identified NPS in SLED, SCRFSC observed the most diverse set of synthetic cannabinoids, and OCCL observed an increased prevalence in the designer benzodiazepine, bromazolam. NPS scope recommendations are a valuable resource for forensic laboratories; however, most focus on a national perspective. Timely analysis and reporting of NPS seized drug data may help to develop regional NPS scope recommendations laboratories may employ.

Emergence of fentanyl-related deaths in Travis County, Texas and surrounding areas: A retrospective review of postmortem fentanyl-related drug toxicities from 2020 to 2022.

The opioid epidemic has affected the United States (US) for decades with fentanyl and its analogs accounting for a recent surge in morbidity and mortality. Currently, there is a relative lack of information characterizing fentanyl-related fatalities specifically in the Southern US. A retrospective study was conducted to examine all postmortem fentanyl-related drug toxicities in Travis County, Texas, encompassing Austin (one of the fastest-growing cities in the US), from 2020 to 2022. Fentanyl contributed to 2.6% and 12.2% of deaths submitted for toxicology between 2020 and 2022, respectively, representing a 375% increase in fentanyl-related deaths over this 3-year period (n = 517). Fentanyl-related fatalities primarily occurred in males in their mid-30s. Fentanyl and norfentanyl concentrations ranged from 0.58 to 320 ng/mL and 0.53 to 140 ng/mL with mean (median) concentrations of 17.2 ± 25.0 (11.0) and 5.6 ± 10.9 (2.9) ng/mL, respectively. Polydrug use was present in 88% of cases, with methamphetamine (or other amphetamines) (25%), benzodiazepines (21%), and cocaine (17%) representing the most frequently identified concurrent substances. Co-positivity rates of various drugs and drug classes widely varied over time. Scene investigations reported illicit powder(s) (n = 141) and/or illicit pill(s) (n = 154) in 48% (n = 247) of fentanyl-related deaths. Illicit oxycodone (44%, n = 67) and illicit "Xanax" (38%, n = 59) pills were frequently reported on scene; however, toxicology only identified oxycodone and alprazolam in 2 and 24 of these cases, respectively. The results of this study provide a better understanding of the fentanyl epidemic in this region creating an opportunity to promote increased awareness, shift focus to harm reduction, and aid in minimizing public health risks.

Subtherapeutic Acetazolamide Doses as a Noninvasive Method for Assessing Medication Adherence.

Adherence monitoring is a vital component of clinical efficacy trials, as the regularity of medication consumption affects both efficacy and adverse effect profiles. Pill-counts do not confirm consumption, and invasive plasma assessments can only assist post hoc assessments. We previously reported on the pharmacokinetics of a potential adherence marker to noninvasively monitor dosage consumption during a trial without breaking a blind. We reported that consumption cessation of subtherapeutic 15 mg acetazolamide (ACZ) doses showed a predictable urinary excretion decay that was quantifiable for an extended period. The current study describes the clinical implementation of 15 mg ACZ doses as an adherence marker excipient in distinct cohorts taking ACZ for different "adherence" durations. We confirm that ACZ output did not change (accumulate) during 18-20 days of adherence, and developed and assessed urinary cutoffs as nonadherence indicators. We demonstrate that whereas an absolute concentration cutoff (989 ng/mL) lacked sensitivity, a creatinine normalized equivalent (1,376 ng/mg ACZ) was highly accurate at detecting nonadherence. We also demonstrate that during nonadherent phases of three trials, creatinine-normalized urinary ACZ elimination was reproducible within and across trials with low variability. Excretion was first order, with a decay half-life averaging ~ 2.0 days. Further, excretion remained quantifiable for 14 days, providing a long period during which the date of last consumption might be determined. We conclude that inclusion of 15 mg ACZ as a dosage form adherence marker excipient, provides a reliable and sensitive mechanism to confirm medication consumption and detect nonadherence during clinical efficacy trials.

Multiple Drug-Toxicity Involving Novel Psychoactive Substances, 3-Fluorophenmetrazine and U-47700.

3-Fluorophenmetrazine (3-FPM) is a stimulant-like novel psychoactive substance (NPS) and fluorinated analog of phenmetrazine that has recently appeared on the recreational drug market, with limited published information. Likewise, the synthetic opioid U-47700 has gained popularity among recreational drug users and is frequently detected in postmortem casework. We present the case history, autopsy and toxicological findings of a fatality involving the designer drugs 3-FPM and U-47700 for the first time in the literature. A sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of 3-FPM in whole blood, with a 0.001-0.100 mg/L analytical range. The method met the requirements for acceptable linearity, bias and precision. 3-FPM was detected along with U-47700 and other drugs including amitriptyline, nortriptyline, methamphetamine, amphetamine, diazepam, nordiazepam, temazepam, and the designer benzodiazepines flubromazolam and delorazepam. 3-FPM was quantified in the decedent's peripheral (femoral) and central (aortic) blood at 2.4 and 2.6 mg/L, respectively. These concentrations are similar to reported concentrations in non-fatal intoxications. U-47700 was present in peripheral blood at a semi-quantitative concentration of 0.36 mg/L, consistent with reported U-47700 postmortem concentrations. The cause of death was considered multiple drug-toxicity (3-FPM, U-47700, amitriptyline, methamphetamine, diazepam, temazepam, flubromazolam and delorazepam) and the manner of death ruled an accident. This case illustrates the dangers of polysubstance use and discusses the potential overlap between recreational and fatal concentrations for some NPS.

Acute effects of intravenous cocaine administration on serum concentrations of ghrelin, amylin, glucagon-like peptide-1, insulin, leptin and peptide YY and relationships with cardiorespiratory and subjective responses.

BACKGROUND: Food intake and use of drugs of abuse like cocaine share common central and peripheral physiological pathways. Appetitive hormones play a major role in regulating food intake; however, little is known about the effects of acute cocaine administration on the blood concentrations of these hormones in cocaine users. METHODS: We evaluated serum concentrations of six appetitive hormones: ghrelin (total and acyl-ghrelin), amylin, glucagon-like peptide-1 (GLP-1), insulin, leptin and peptide YY (PYY), as well as acute cardiorespiratory and subjective responses of 8 experienced cocaine users who received 25mg intravenous (IV) cocaine. RESULTS: Serum concentrations of GLP-1 (p=0.014) and PYY (p=0.036) were significantly decreased one hour following IV cocaine administration; there was a trend towards a decrease for insulin (p=0.055) and amylin (p=0.063) concentrations, while no significant IV cocaine effect was observed for ghrelin (total or acyl-ghrelin) or leptin concentrations (p's≫>0.5). We also observed associations between hormone concentrations acutely affected by IV cocaine (GLP-1, PYY, insulin, amylin) and some cocaine-related cardiorespiratory and subjective responses (e.g., increased heart and respiratory rates; feeling high and anxious). DISCUSSION: These findings show a significant effect of acute IV cocaine administration on some appetitive hormones and suggest potential associations between these hormones and cocaine-related cardiorespiratory and subjective responses. Additional research is needed to further investigate the potential mechanisms underlining these associations.

Pharmacokinetic Profiles and Pharmacodynamic Effects for Methylone and Its Metabolites in Rats.

3,4-Methylenedioxy-N-methylcathinone (methylone) is a new psychoactive substance and the ß-keto analog of 3,4-methylenedioxy-N-methylamphetamine (MDMA). It is well established that MDMA metabolism produces bioactive metabolites. Here we tested the hypothesis that methylone metabolism in rats can form bioactive metabolites. First, we examined the pharmacokinetics (PKs) of methylone and its metabolites after subcutaneous (sc) methylone administration (3, 6, 12 mg/kg) to male rats fitted with intravenous (iv) catheters for repeated blood sampling. Plasma specimens were assayed by liquid chromatography tandem mass spectrometry to quantify methylone and its phase I metabolites: 3,4-methylenedioxycathinone (MDC), 3,4-dihydroxy-N-methylcathinone (HHMC), and 4-hydroxy-3-methoxy-N-methylcathinone (HMMC). The biological activity of methylone and its metabolites was then compared using in vitro transporter assays and in vivo microdialysis in rat nucleus accumbens. For the PK study, we found that methylone and MDC peaked early (Tmax=15-45 min) and were short lived (t1/2=60-90 min), while HHMC and HMMC peaked later (Tmax=60-120 min) and persisted (t1/2=120-180 min). Area-under-the-curve values for methylone and MDC were greater than dose-proportional, suggesting non-linear accumulation. Methylone produced significant locomotor activation, which was correlated with plasma methylone, MDC, and HHMC concentrations. Methylone, MDC, and HHMC were substrate-type releasers at monoamine transporters as determined in vitro, but only methylone and MDC (1, 3 mg/kg, iv) produced significant elevations in brain extracellular dopamine and 5-HT in vivo. Our findings demonstrate that methylone is extensively metabolized in rats, but MDC is the only centrally active metabolite that could contribute to overall effects of the drug in vivo.

Synthetic cathinone pharmacokinetics, analytical methods, and toxicological findings from human performance and postmortem cases.

Synthetic cathinones are commonly abused novel psychoactive substances (NPS). We present a comprehensive systematic review addressing in vitro and in vivo synthetic cathinone pharmacokinetics, analytical methods for detection and quantification in biological matrices, and toxicological findings from human performance and postmortem toxicology cases. Few preclinical administration studies examined synthetic cathinone pharmacokinetic profiles (absorption, distribution, metabolism, and excretion), and only one investigated metabolite pharmacokinetics. Synthetic cathinone metabolic profiling studies, primarily with human liver microsomes, elucidated metabolite structures and identified suitable biomarkers to extend detection windows beyond those provided by parent compounds. Generally, cathinone derivatives underwent ketone reduction, carbonylation of the pyrrolidine ring, and oxidative reactions, with phase II metabolites also detected. Reliable analytical methods are necessary for cathinone identification in biological matrices to document intake and link adverse events to specific compounds and concentrations. NPS analytical methods are constrained in their ability to detect new emerging synthetic cathinones due to limited commercially available reference standards and continuous development of new analogs. Immunoassay screening methods are especially affected, but also gas-chromatography and liquid-chromatography mass spectrometry confirmation methods. Non-targeted high-resolution-mass spectrometry screening methods are advantageous, as they allow for retrospective data analysis and easier addition of new synthetic cathinones to existing methods. Lack of controlled administration studies in humans complicate interpretation of synthetic cathinones in biological matrices, as dosing information is typically unknown. Furthermore, antemortem and postmortem concentrations often overlap and the presence of other psychoactive substances are typically found in combination with cathinones derivatives, further confounding result interpretation.

First metabolic profile of PV8, a novel synthetic cathinone, in human hepatocytes and urine by high-resolution mass spectrometry.

Novel psychoactive substances (NPS) are ever changing on the drug market, making it difficult for toxicology laboratory methods to stay current with so many new drugs. Recently, PV8, a synthetic pyrrolidinophenone, was detected in seized products in Japan (2013), The Netherlands (2014), and Germany (2014). There are no controlled PV8 administration studies, and no pharmacodynamic and pharmacokinetic data. The objective was to determine PV8's metabolic stability in human liver microsome (HLM) incubation and its metabolism following human hepatocyte incubation and high-resolution mass spectrometry (HRMS) with a Thermo Scientific Q-Exactive. Data were acquired with a full-scan data-dependent mass spectrometry method. Scans were thoroughly data mined with different data processing algorithms and analyzed in WebMetaBase. PV8 exhibited a relatively short 28.8 min half-life, with an intrinsic 24.2 µL/min/mg microsomal clearance. This compound is predicted to be an intermediate clearance drug with an estimated human 22.7 mL/min/kg hepatic clearance. Metabolic pathways identified in vitro included: hydroxylation, ketone reduction, carboxylation, N-dealkylation, iminium formation, dehydrogenation, N-oxidation, and carbonylation. The top three in vitro metabolic pathways were di-hydroxylation > ketone reduction > γ-lactam formation. Authentic urine specimen analyses revealed the top three metabolic pathways were aliphatic hydroxylation > ketone reduction + aliphatic hydroxylation > aliphatic carboxylation, although the most prominent peak was parent PV8. These data provide useful urinary metabolite targets (aliphatic hydroxylation, aliphatic hydroxylation + ketone reduction, aliphatic carboxylation, and di-hydroxylation) for forensic and clinical testing, and focus reference standard companies' synthetic efforts to provide commercially available standards needed for PV8 biological specimen testing. Graphical Abstract Top four PV8 metabolites identified in vitro. Biotransformations highlighted in blue. Markush structures presented when exact location of biotransformation is unknown.

Pharmacodynamic effects and relationships to plasma and oral fluid pharmacokinetics after intravenous cocaine administration.

BACKGROUND: No controlled cocaine administration data describe cocaine and metabolite disposition in oral fluid (OF) collected with commercially-available collection devices, OF-plasma ratios, and pharmacodynamic relationships with plasma and OF cocaine and metabolite concentrations. METHODS: Eleven healthy, cocaine-using adults received 25mg intravenous cocaine. Physiological and subjective effects (visual analogue scales), and plasma were collected one hour prior, and up to 21h post-dose. OF was collected with the Quantisal™ device up to 69h post-dose. Cocaine, benzoylecgonine (BE) and ecgonine methyl ester were quantified in plasma by liquid chromatography-tandem mass spectrometry; cocaine and BE were quantified in OF by two dimensional-gas chromatography-mass spectrometry. RESULTS: Increases in heart rate, blood pressure and positive subjective effects occurred within the first 15min, persisting up to 1h ("Rush"), with clockwise hysteresis observed for plasma and OF concentrations and some subjective measures. Peak subjective effects ("Rush," "Good drug effect" and "Bad drug effect") occurred prior to peak OF cocaine concentration, whereas observed peak plasma concentrations and subjective measures occurred simultaneously, most likely due to significantly earlier plasma Tmax compared to OF Tmax.Tlast was generally longer in OF (12.5h cocaine; 33.0h BE) than plasma (9.5h cocaine; >21h BE, cutoffs 1µg/L); 8 and 10µg/L OF cocaine confirmatory cutoffs yielded detection times similar to cocaine's impairing effects, suggesting usefulness for DUID testing. CONCLUSIONS: OF offers advantages as an alternative matrix to blood and plasma for identifying cocaine intake, defining pharmacokinetic parameters at different confirmation cutoffs, and aiding different drug testing programs to best achieve their monitoring goals.

Cocaine and benzoylecgonine oral fluid on-site screening and confirmation.

Accurate on-site devices to screen for drug intake are critical for establishing whether an individual is driving under the influence of drugs (DUID); however, on-site oral fluid (OF) cocaine device performance is variable. We evaluated the performance of a newly developed benzoylecgonine (BE) test-strip for the Draeger® DrugTest 5000 device (20 µg/L cut-off) with equivalent cross reactivity for cocaine and BE. Ten cocaine users provided OF, collected with the Draeger cassette and Oral-Eze® and StatSure Saliva Sampler(TM) devices, up to 69 h following 25 mg intravenous cocaine administration. All screening results were confirmed by a validated two-dimensional-gas chromatography-mass spectrometry (2D-GC-MS) method for cocaine and/or BE. Cocaine test-strip median Tlast for screening only results was 6.5 h, and 6.5 h with Oral-Eze® and 4 h for StatSure OF confirmation for cocaine and/or BE at 1, 8, and 10 µg/L; sensitivity, specificity, and efficiency ranged from 85.5 to 100% and 83.3 to 100% for cocaine only confirmation at 8 and 10 µg/L. For the BE test-strip, median Tlast was 12.5 h for screening only and confirmation for cocaine and/or BE at all three cut-offs; sensitivity, specificity, and efficiency ranged from 85.5 to 97.5% and 78.4 to 97.4% with cocaine and/or BE confirmation at 8 and 10 µg/L cut-offs, respectively. The Draeger cocaine test-strip with cocaine only confirmation offers a useful option for monitoring the acute intoxication phase of DUID; additionally the BE test-strip with cocaine and/or BE confirmation increases the length of detection of cocaine intake for workplace drug testing, drug court, parole, pain management, drug treatment programs and both the acute cocaine intoxication and cocaine crash/fatigue phase of DUID. Copyright © 2016 John Wiley & Sons, Ltd.

Oral fluid cocaine and benzoylecgonine concentrations following controlled intravenous cocaine administration.

Limited oral fluid (OF) pharmacokinetic data collected with commercially available collection devices after controlled cocaine administration hinder OF result interpretations. Ten cocaine-using adults provided OF, collected with Oral-Eze(®) (OE) and StatSure Saliva Sampler™ (SS) devices, an hour prior to and up to 69 h after 25mg intravenous (IV) cocaine administration. Cocaine and benzoylecgonine (BE) were quantified by a validated 2D-GC-MS method. Large inter-subject variability was observed. Cocaine was detected in OF in the first 0.17 h sample after IV administration, with much more rapid elimination than BE. OE observed Cmax median (range) concentrations were 932 (394-1574)µg/L for cocaine and 248 (96.9-953)µg/L for BE. SS observed cocaine and BE Cmax median (range) concentrations trended lower at 732 (83.3-1892)µg/L and 360 (77.2-836)µg/L, respectively. OE and SS cocaine OF detection times were 12.5 and 6.5h and for BE 30.5 and 28.0 h, respectively at 1 µg/L. There were no significant pharmacokinetic differences between OE and SS OF collection devices, except cocaine half-life was significantly shorter in SS OF specimens. This difference could be attributed to differences in stabilizing buffers present in OF collection devices, which may affect cocaine stability in OF specimens, or decreased recovery from collection pads. Both OE and SS OF collection devices were effective in monitoring cocaine and metabolite concentrations with similar detection windows. Furthermore, we demonstrated that different confirmatory OF cutoffs can be selected to produce shorter or longer cocaine and metabolite detection windows to address specific needs of clinical and forensic drug testing programs.

4-Methoxy-α-PVP: in silico prediction, metabolic stability, and metabolite identification by human hepatocyte incubation and high-resolution mass spectrometry.

Novel psychoactive substances are continuously developed to circumvent legislative and regulatory efforts. A new synthetic cathinone, 4-methoxy-α-PVP, was identified for the first time in illegal products; however, the metabolism of this compound is not known. Complete metabolic profiles are needed for these novel psychoactive substances to enable identification of their intake and to link adverse effects to the causative agent. This study assessed 4-methoxy-α-PVP metabolic stability with human liver microsomes (HLMs) and identified its metabolites after HLM and hepatocyte incubations followed by high-resolution mass spectrometry (HRMS). A Thermo QExactive high-resolution mass spectrometer (HRMS) was used with full scan data-dependent mass spectrometry, with (1) and without (2) an inclusion list of predicted metabolite, and with full scan and all-ion fragmentation (3) to identify potential unexpected metabolites. In silico predictions were performed and compared to in vitro results. Scans were thoroughly mined with different data processing algorithms using WebMetabase (Molecular Discovery). 4-Methoxy-α-PVP exhibited a long half-life of 79.7 min in HLM, with an intrinsic clearance of 8.7 µL min-1 mg-1. In addition, this compound is predicted to be a low-clearance drug with an estimated human hepatic clearance of 8.2 mL min-1 kg-1. Eleven 4-methoxy-α-PVP metabolites were identified, generated by O-demethylation, hydroxylation, oxidation, ketone reduction, N-dealkylation, and glucuronidation. The most dominant metabolite in HLM and human hepatocyte samples was 4-hydroxy-α-PVP, also predicted as the #1 in silico metabolite, and is suggested to be a suitable analytical target in addition to the parent compound.

In vitro, in vivo and in silico metabolic profiling of α-pyrrolidinopentiothiophenone, a novel thiophene stimulant.

BACKGROUND: Little or no pharmacological or toxicological data are available for novel psychoactive substances when they first emerge, making their identification and interpretation in biological matrices challenging. MATERIALS & METHODS: A new synthetic cathinone, α-pyrrolidinopentiothiophenone (α-PVT), was incubated with hepatocytes and samples were analyzed using liquid chromatography coupled to a Q Exactive™ Orbitrap mass spectrometer. Authentic urine specimens from suspected α-PVT cases were also analyzed. Scans were data mined with Compound Discoverer™ for identification and structural elucidation of metabolites. RESULTS/CONCLUSION: Seven α-PVT metabolites were identified in hepatocyte incubations, and in the authentic urine samples, also with an additional monohydroxylated product and a glucuronide of low intensity. α-PVT dihydroxypyrrolidinyl, α-PVT 2-ketopyrrolidinyl, α-PVT hydroxythiophenyl and α-PVT thiophenol had the most intense in vivo signals.

Cocaine and metabolite concentrations in DBS and venous blood after controlled intravenous cocaine administration.

BACKGROUND: DBS are an increasingly common clinical matrix. METHODS & RESULTS: Sensitive and specific methods for DBS and venous blood cocaine and metabolite detection by LC-HRMS and 2D GC-MS, respectively, were validated to examine correlation between concentrations following controlled intravenous cocaine administration. Linear ranges from 1 to 200 µg/l were achieved, with acceptable bias and imprecision. Authentic matched specimens' (392 DBS, 97 venous blood) cocaine and benzoylecgonine concentrations were qualitatively similar, but DBS had much greater variability (21.4-105.9 %CV) and were lower than in blood. CONCLUSION: DBS offer advantages for monitoring cocaine intake; however, differences between capillary and venous blood and DBS concentration variability must be addressed.

Quantification of cocaine and metabolites in exhaled breath by liquid chromatography-high-resolution mass spectrometry following controlled administration of intravenous cocaine.

Breath has been investigated as an alternative matrix for detecting recent cocaine intake; however, there are no controlled cocaine administration studies that investigated the drug's disposition into breath. Breath was collected from 10 healthy adult cocaine users by asking them to breathe into a SensAbues device for 3 min before and up to 22 h following 25 mg intravenous (IV) cocaine dosing on days 1, 5, and 10, and assayed with a validated liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method to quantify breath cocaine, benzoylecgonine (BE), ecgonine methyl ester (EME), and norcocaine. The assay was linear from 25 to 1,000 pg/filter, extraction efficiencies were 83.6-126%, intra- and inter-assay imprecision was <10.6%, and bias was between -8.5 and 16.8%. No endogenous or exogenous interferences were observed for more than 75 tested. Analytes were generally stable under short-term storage conditions. Ion suppression was less than 46%. Of breath specimens collected after controlled cocaine administration, 2.6% were positive for cocaine (26.1-66 pg/filter, 1-9.5 h), 0.72% BE (83.3-151 pg/filter, 6.5-12.5 h), and 0.72% EME (50-69.1 pg/filter, 6.5-12.5 h); norcocaine was not detected. Methanolic extraction of the devices themselves, after filters were removed, yielded 19.2% positive cocaine tests (25.2-36.4 pg/device, 10 min-22 h) and 4.3% positive BE tests (26.4-93.7 pg/device, 10 min-22 h), explaining differences between the two extraction techniques. These results suggest that the device reflects the drug in oral fluid as well as lung microparticles, while the filter reflects only drug-laden microparticles. A sensitive and specific method for cocaine, BE, EME, and norcocaine quantification in breath was developed and validated. Cocaine in breath identifies recent cocaine ingestion, but its absence does not preclude recent use.

Validation of the only commercially available immunoassay for synthetic cathinones in urine: Randox Drugs of Abuse V Biochip Array Technology.

Deterrence of synthetic cathinone abuse is hampered by the lack of a high-throughput immunoassay screen. The Randox Drugs of Abuse V (DOA-V) Biochip Array Technology contains two synthetic cathinone antibodies: Bath Salt I (BSI) targets mephedrone/methcathinone and Bath Salt II (BSII) targets 3',4'-methylenedioxypyrovalerone (MDPV)/3',4'-methylenedioxy-α-pyrrolidinobutiophenone (MDPBP). We evaluated DOA-V synthetic cathinones performance and conducted a full validation on the original assay with calibrators reconstituted in water, and the new assay with calibrators prepared in lyophilized urine; both utilized the same antibodies and were run on the fully automated Evidence® Analyzer. We screened 20 017 authentic military urine specimens and confirmed positives by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for 28 synthetic cathinones. Limits of detection (LOD) for the original and new assays were 0.35 and 0.18 (BSI), and 8.5 and 9.2 µg/L (BSII), respectively. Linearity was acceptable (R(2) >0.98); however, a large negative bias was observed with in-house prepared calibrators. Intra-assay imprecision was <20% BSI-II, while inter-assay imprecision was 18-42% BSI and <22% BSII. Precision was acceptable for Randox controls. Cross-reactivities of many additional synthetic cathinones were determined. Authentic drug-free negative urine pH <4 produced false positive results for BSI (6.3 µg/L) and BSII (473 µg/L). Oxidizing agents reduced BSI and increased BSII results. Sensitivity, specificity, and efficiency of 100%, 52.1%, and 53.0% were obtained at manufacturer's proposed cut-offs (BSI 5 µg/L, BSII 30 µg/L). Performance improved if cut-off concentrations increased (BSI 7.5 µg/L, BSII 40 µg/L); however, there were limited confirmed positive specimens. Currently, this is the first and only fully validated immunoassay for preliminary detection of synthetic cathinones in urine. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Examination of some performance characteristics of breath alcohol measurements obtained with the intoxilyzer 8000C following social drinking conditions.

The Intoxilyzer 8000C was used to measure breath alcohol concentration (BrAC) in 10 healthy subjects under social drinking conditions. Measurements commenced within 5 min of the end of drinking (EOD). For 14 blood-breath pairs, measured BrACs were compared to corresponding venous blood alcohol concentrations (vBAC) of samples drawn at least 30 min after EOD and within 5 min of the corresponding breath test. BAC was analyzed using an enzymatic method. Concentration differences between breath and blood (BrAC - vBAC) ranged from -32 to +3 mg/dL (untruncated BrAC) and from -32 to -4 mg/dL (truncated BrAC). The Invalid Sample message was actuated in five out of 23 BrAC profiles. In the remaining 18 samples, residual mouth alcohol was evaluated by comparing the maximum difference between successive (5 min apart) measurements (MID5) over 20-30 min after EOD with the precision of replicate BrAC values taken 30-40 min after EOD (5 mg/dL or less; precision unaffected by breath sample volume over the range of 2-3 L). MID5 values occurred within the first three measurements in 16/18 cases, indicative of a significant mouth alcohol effect. Thus, mandatory delays should be used with the Intoxilyzer 8000C prior to testing to minimize the probability of overestimation of BrAC due to mouth alcohol.