Norketamine Research Articles

Rapid on-site detection of illicit drugs in urine using C18 pipette-tip based solid-phase extraction coupled with a miniaturized mass spectrometer

Drug abuse is a social issue worldwide, and there is an increasing demand for on-site rapid detection of illicit drugs. In this study, a rapid and simple analytical method for the detection of 6-monoacetylmorphine (6-MAM), methamphetamine (MA), methylenedioxymethamphetamine (MDMA), ketamine (K), norketamine (NK), and cocaine (COC) in urine was developed. The developed method combines C18 pipette-tip based solid-phase extraction (C18 PT-SPE) with a miniaturized mass spectrometer (miniMS), exhibiting remarkable simplicity, high sensitivity, and strong reliability, compared with the conventional method. The optimal extraction and elution conditions for C18 PT-SPE were considered as 9 and 3 aspirating-dispensing cycles, respectively. The miniMS parameters including spray voltage, isolation potential, and collision-induced dissociation energy for the detection of these six illicit drugs were optimized using a nano-electrospray ionization method. The limit of detection (LOD), limit of quantification (LOQ), linear range, and linearity for the analysis of six illicit drugs in urine with the proposed C18 PT-SPE-miniMS method were determined. Except for the LOD of K and COC was determined as 0.5 and 0.25 ng mL−1 respectively, and the LOD of 6-MAM MA, MDMA, and NK was determined as 1 ng mL−1. This method enables rapid on-site detection, providing easier operation, lower cost, and better portability compared to conventional methods, making it a potential tool in drug crime investigation and forensic science.

A Broadly Applicable Diels-Alder-Based Synthesis of Ketamine-Related Arylcyclohexylamines.

Herein, we report the synthesis of aryl derivatives of ketamine and of ketamine's major metabolites hydroxynorketamine (HNK), norketamine (NK), and dehydronorketamine (DHNK) via a microwave-assisted Diels-Alder reaction to form the substituted cyclohexane core structure. Starting with aryl acrylic esters as dienophiles and siloxybutadienes as diene counterparts, a wide range of substituted arylcyclohexylamines was obtained after several modification steps of the initial Diels-Alder products [El Sheikh, S.; Weber, H.; Kortenbrede, L.; Drouvé, N. A broadly applicable Diels-Alder based Synthesis of Ketamine related Arylcyclohexylamines. ChemRxiv 2022, 10.26434/chemrxiv- 2022-xf1l9].

A Review of the Metabolism and Relevance to Form and Formulation of Ketamine

IntroductionKetamine is a phenylcyclohexylamine derivative comprising a racemic mixture of S- and R-ketamine that possesses anesthetic, analgesic, anti-inflammatory, and antidepressant activity. Oral (including extended release [PO]), intravenous (IV) sublingual (SL), transmucosal (TM), intranasal (IN), intramuscular (IM), rectal (PR), and subcutaneous (SC) formulations have been developed since its commercialization in 1970.ObjectivesTo review and understand the impact of different forms and formulations on the pharmacokinetics of ketamine.MethodsThe extant literature on ketamine metabolism and formulations was reviewed and discussed.ResultsIV (racemic) ketamine (KET) has been shown to improve depressed mood within 4 hours with maximal effect at 24 hours. KET is a chiral molecule with two optimal isomers, R- and S-KET. KET is stereoselectively metabolized by CYP2B6 and CYP3A4 initially via nitrogen demethylation to active metabolite, norketamine (NK); there is no interconversion between R- and S-KET. NK is further metabolized to hydroxynorketamine (HNK) by CYP3A4 and CYP3A5; and dehydronorketamine (DHNK) by CYP2B6. Additional metabolic pathways exist including a direct enantioselective hydroxylation of KET to 6-hydroxyketamine (HK). Bioavailablity is greatest (100%) with the IV racemic KET formulation, but as low as 8% for oral S-KET due to extensive first-pass metabolism; the KET: NK ratio is a measure of first pass metabolism. NK plasma levels are higher with oral S-KET than KET as a result of local intestinal metabolism effects. Additionally, greater plasma concentrations are noted with IV bolus doses of S-KET vs. racemic KET or R-KET. S-KET possesses a longer elimination half-life than racemic KET due to inhibition by R-KET. KET is primarily renally eliminated and twice as fast in children vs. adults.ConclusionsComplex interactions are reported between ketamine form (racemic/enantiomer), formulation, dose, and route of administration that impact on clinical variables and thus, outcome.Disclosure of InterestNone Declared

Chiral LC-MS/MS method for the simultaneous determination of (R,S)-ketamine, (R,S)-norketamine, and (2R,6R;2S,6S)-hydroxynorketamine in mouse plasma and brain

A convenient LC-MS/MS assay method to simultaneously and sensitively determine (R,S)-ketamine (Ket), (R,S)-norketamine (NK), and (2R,6R;2S,6S)-hydroxynorketamine (HNK) enantiomers in plasma and brain from mice was developed. This method enables the chiral separations of these six enantiomers in one analysis by constructing a column-switching system composed of one achiral column and two chiral columns with a relatively short analysis time (17 min). The chromatography involves the separation of (2R,6R;2S,6S)-HNK from (R,S)-Ket and (R,S)-NK on an octadecyl-silica column, followed by chiral separations on a CHIRALPAK AY-RH column for (2R,6R;2S,6S)-HNK or on a CHIRALPAK AS-RH column for the other analytes. The calibration curves for plasma and brain showed a good linearity in the range of 3–1000 ng/mL and 1.5–500 ng/g, respectively. The accuracy ranged from 90.0% to 104.0% in within-run and between-run. This validated method was applicable to determine the stereoselective pharmacokinetic profiles of (R,S)-Ket, (R,S)-NK, and (2R,6R;2S,6S)-HNK in plasma and brain collected from individual mice after a single intraperitoneal dosing of racemic Ket at an antidepressant dose. It is hoped that this assay will greatly help for understanding the relationship between the antidepressant actions of (R,S)-Ket enantiomers or their metabolites and their pharmacokinetics.

Norketamine, the Main Metabolite of Ketamine, Induces Mitochondria-Dependent and ER Stress-Triggered Apoptotic Death in Urothelial Cells via a Ca2+-Regulated ERK1/2-Activating Pathway.

Ketamine-associated cystitis is characterized by suburothelial inflammation and urothelial cell death. Norketamine (NK), the main metabolite of ketamine, is abundant in urine following ketamine exposure. NK has been speculated to exert toxic effects in urothelial cells, similarly to ketamine. However, the molecular mechanisms contributing to NK-induced urothelial cytotoxicity are almost unclear. Here, we aimed to investigate the toxic effects of NK and the potential mechanisms underlying NK-induced urothelial cell injury. In this study, NK exposure significantly reduced cell viability and induced apoptosis in human urinary bladder epithelial-derived RT4 cells that NK (0.01–0.5 mM) exhibited greater cytotoxicity than ketamine (0.1–3 mM). Signals of mitochondrial dysfunction, including mitochondrial membrane potential (MMP) loss and cytosolic cytochrome c release, were found to be involved in NK-induced cell apoptosis and death. NK exposure of cells also triggered the expression of endoplasmic reticulum (ER) stress-related proteins including GRP78, CHOP, XBP-1, ATF-4 and -6, caspase-12, PERK, eIF-2α, and IRE-1. Pretreatment with 4-phenylbutyric acid (an ER stress inhibitor) markedly prevented the expression of ER stress-related proteins and apoptotic events in NK-exposed cells. Additionally, NK exposure significantly activated JNK, ERK1/2, and p38 signaling and increased intracellular calcium concentrations ([Ca2+]i). Pretreatment of cells with both PD98059 (an ERK1/2 inhibitor) and BAPTA/AM (a cell-permeable Ca2+ chelator), but not SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor), effectively suppressed NK-induced mitochondrial dysfunction, ER stress-related signals, and apoptotic events. The elevation of [Ca2+]i in NK-exposed cells could be obviously inhibited by BAPTA/AM, but not PD98059. Taken together, these findings suggest that NK exposure exerts urothelial cytotoxicity via a [Ca2+]i-regulated ERK1/2 activation, which is involved in downstream mediation of the mitochondria-dependent and ER stress-triggered apoptotic pathway, consequently resulting in urothelial cell death. Our findings suggest that regulating [Ca2+]i/ERK signaling pathways may be a promising strategy for treatment of NK-induced urothelial cystitis.

Wastewater-based monitoring of 2-fluoro-deschloroketamine abuse from 2019 to 2021 in a southern Chinese province

2-fluoro-deschloroketamine (FDCK) is a ketamine (KET) analog and new psychoactive substance that has appeared on the drug market in Europe and China in the past few years. The substance has been recently listed as a controlled drug by the narcotics control authority of China. In this work, FDCK and its metabolite nor-fluoro-deschloroketmaine (N-FDCK) in wastewater were analyzed for the first time to monitor FDCK abuse in a southern Chinese province that used to be a major producer and consumer of ketamine. For comparison, KET and its metabolite, nor-ketamine (N-KET) were monitored simultaneously. The concentration ratios between FDCK and N-FDCK were not statistically different from those of KET and N-KET. The average FDCK loads in the province in 2019 were higher than KET loads in most major cities in China in 2014 (when KET abuse hit its peak in the country). Rough estimation of FDCK and KET consumption revealed that FDCK was the predominant synthetic drug in the province in 2019, indicating rapid spread of the substance since its first appearance on the market. FDCK consumption decreased dramatically in 2020 and 2021, due to proactive actions by the local drug police before its listing as a controlled drug. Despite the dramatic decrease, FDCK was still the drug with greatest consumption by 2021, indicating that this substance persisted on the market even in the presence of forceful law enforcement. This finding also demonstrates that this substance may indeed have similar or even improved psychoactive effects relative to KET. Quick spread and persistence of FDCK demonstrated here indicates the urgent need to conduct wastewater-based monitoring of the abuse of the substance in other Chinese provinces and other countries.

Development of a rapid and sensitive LC-MS/MS assay for the quantification of commonly abused drugs in Asia in a micro-segment of a single hair using microwave-assisted extraction and dansyl chloride derivatization

A high-throughput method using microwave-assisted extraction, chemical derivatization and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) was developed for the simultaneous analysis of illicit drugs and their metabolites, including amphetamine (AMP), methamphetamine (MA), methylenedioxy- amphetamine (MDA), methylenedioxy-methamphetamine (MDMA), morphine (MOR), 6-acetylmorphine (6-AM), ketamine (K), and norketamine (NK) in a micro-segment of a single hair (0.4 mm). In order to elevate the throughput and sensitivities of selected compounds, 3 min microwave-assisted extraction and 10 min derivatization with dansyl chloride (DC) were employed. After derivatization, all compounds except ketamine and norketamine were derivatized and enhanced the sensitivities significantly. Derivatives showed intense fragment ions and low background noise on DC-MOR, DC-6-AM, and four DC-amphetamine-type stimulants. The total sample preparation and analysis time was 50 min. The calibration range was from LOQ to 5000 pg/mg, the coefficient of determination was better than 0.997. Intra-assay precision and accuracy were generally less than 15%. Limits of detection ranged from 15 to 50 pg/mg, limits of quantitation ranged between 45 and 125 pg/mg. The matrix effect was better than 90%. The method was successfully applied to the analysis of actual hair samples collected from multi-drug abusers. This advanced method showed practicality in hair analysis and was suitable for the extremely insufficient sample.

Synthesis of a novel polydopamine and C18 dual-functionalized magnetic core-shell mesoporous nanocomposite for enrichment and analysis of widely abused illegal drugs in urine samples on site and in the laboratory

In this study, a novel polydopamine and C18 dual-functionalized magnetic core-shell mesoporous silica (Fe3O4@nSiO2@mSiO2@PDA-C18) nanocomposite was designed and synthesized, which was employed as an adsorbent to extract illegal drugs from urine samples by magnetic solid-phase extraction (MSPE) procedures. The as-prepared nanocomposite was fully characterized and combined with ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to monitor 12 trace illegal drugs and metabolites, including 6-monoacetylmorphine (6-MAM), morphine (MOR), codeine (COD), amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), ketamine (KET), norketamine (NK), cocaine (COC), benzoylecgonine (BZE) and methcathinone (MC). Optimal MSPE procedures were achieved by fully investigating parameters of activation, adsorption, washing and desorption steps. The MSPE-UHPLC-MS/MS method offered high sensitivity with limit of detection (LOD) range of 0.005–0.05 ng mL-1 and good linearity with the concentration of 0.01–1000 ng mL-1. Also, the intra- and inter-day recovery respectively ranged in 90.2–105.0% and 89.8–107.4%, and the intra- and inter-day precision was in the range of 0.5–14.0% and 1.2–10.0%, respectively. By application to real urine samples, the proposed method could not only be equally sensitive for quantifying 12 illegal drugs in urine but also significantly reduce the pretreatment time when comparing with methods based on solid-phase extraction. Furthermore, the designed dual-functionalized adsorbents could also be applied for on-site determination of MAMP in urine coupled with urine test kit, and the detection threshold of MAMP urine test kit remarkably reduced from 1000 ng mL-1 to 50 ng mL-1. Therefore, the present method was a convenient, economic and sensitive approach for determining illegal drugs in urine samples both on site and in the laboratory.

Enantioselective Monitoring of Biodegradation of Ketamine and Its Metabolite Norketamine by Liquid Chromatography

Ketamine (K) and its main metabolite, norketamine (NK), are chiral compounds that have been found in effluents from wastewater treatment plants (WWTPs) and aquatic environments. Little is known about their enantioselective biodegradation during sewage treatment; however, this information is pivotal for risk assessment, the evaluation of WWTP performance and wastewater epidemiological studies. The aim of this study was to investigate the biodegradation pattern of the enantiomers of K by activated sludge (AS) from a WWTP. For that, an enantioselective liquid chromatography with diode array detection (LC-DAD) method was developed and validated to quantify the enantiomers of K and NK. Both K and NK enantiomers were separated, in the same chromatographic run, using a Lux® 3 µm cellulose-4 analytical column under isocratic elution mode. The method was demonstrated to be linear (r2 > 0.99) and precise (<11.3%). Accuracy ranged between 85.9 and 113.6% and recovery ranged between 50.1 and 86.9%. The limit of quantification was 1.25 µg/mL for the enantiomers of NK and 2.5 µg/mL for K. The method was applied to monitor the biodegradation assay of the enantiomers of K by AS for 14 days. K was poorly biodegraded, less than 15% for both enantiomers, and enantioselectivity in the biodegradation was not observed. The metabolite NK and other possible degradation products were not detected. This work reports, for the first time, the behavior of both enantiomers of K in biodegradation studies.

Tissue-specific accumulation, elimination, and toxicokinetics of illicit drugs in adult zebrafish (Danio rerio)

The abuse of illicit drugs has led to their extensive detection worldwide and subsequently exerted adverse effects upon aquatic organisms and ecosystem. However, less attention has been paid to the uptake, biotransformation, internal distribution, and toxicokinetic processes in the exposed organisms. In this study, zebrafish (Danio rerio) was exposed to methamphetamine (METH) and ketamine (KET) at three different concentrations in a semi-static exposure system. METH and KET, together with their metabolites, amphetamine (AMP) and norketamine (NK), were consistently detected in zebrafish. Over 14-day exposure, the relative magnitude of mean concentrations of illicit drugs in zebrafish generally followed the order of brain > liver > intestine > ovary > muscle. The uptake rate constants (Ku) of METH and KET were in the range of 0.590–1.38 × 103 L/(kg·d), the elimination rate constants (Ke) were in the range of 0.18–6.98 1/d, and the half-lives were in the range of 0.18–6.98 d, respectively. METH and KET demonstrated relatively rapid uptake and elimination kinetics and short half-lives, and concentrations in organs were driven by external concentrations. Illicit drugs were not persistent within zebrafish organs when there were no substantial external contaminant sources. The observed values of bioconcentration factor (BCFo, L/kg) and kinetically-derived bioconcentration factor (BCFk, L/kg) were at the similar level. The ability of different zebrafish organs accumulating target chemicals from the aquatic environment was different, and brain was the target organ of the test illicit drugs.

Estimation of the psychoactive substances consumption within 12 wastewater treatment plants service areas in a certain city of Guangxi, China applying wastewater-based epidemiology.

The abuse of psychoactive substances has been increasing dramatically over the last few years, which is becoming a concern for human health and social stability. How to accurately estimate psychoactive substances' total consumption in certain areas is the key to manage such substances. In order to control psychoactive substances, 8 psychoactive substances' consumption within 12 wastewater treatment plants (WWTPs) service areas in a certain city of Guangxi, China was investigated in 2019. Firstly, a solid-phase extraction-liquid chromatography-tandem mass spectrometry method was used to determine the influent concentrations. Morphine (MOR), 3, 4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH), ketamine (KET), and norketamine (NK) were detected, with the concentrations ranging from less than method detection limit (NK, MDMA) to 170.91 (METH) ng/L. Then, the back-estimation of consumption was conducted according to the objective and near real-time wastewater-based epidemiology (WBE). The results demonstrate that KET, MOR, and METH are the most abused psychoactive substances, with the mean consumption of 682.42, 167.81, and 44.56mg/day/1000inh, respectively. The psychoactive substance residues of WWTPs influent were analyzed to estimate such substances' consumption in specific areas, so as to provide support for risk prevention and control.

Simultaneous enantioselective analysis of illicit drugs in wastewater and surface water by chiral LC-MS/MS: A pilot study on a wastewater treatment plant and its receiving river.

An enantioselective method for quantifying amphetamine-type chiral illicit drugs (CIDs) in wastewater and surface water was developed, validated, and applied to samples from a wastewater treatment plant (WWTP) and its effluent-receiving river in Beijing, China. Water samples were subjected to solid-phase extraction (SPE) and then quantified via liquid chromatography-tandem mass spectrometry. The enantioseparation of CIDs was performed with a CHIRALPAK CBH column. Chromatographic parameters, including mobile phase composition and flow rates, were tested to identify the satisfactory enantiomeric resolution. The SPE method was optimized by evaluating variables, including SPE cartridge types, extraction solvents, and solvent volumes. The Oasis HLB sorbent showed good performance with recoveries exceeding 60% and matrix effects ranging from-19.6% to 26.6% for most target enantiomers, except for norephedrine (NE), in three different aquatic matrixes. The established method was superior to previously reported methods and had a low limit of detection, low limit of quantification, and short runtime (<45min). The repeatability and reproducibility of the method reached 19.1% and 17.8%, respectively. The method was successfully utilized to monitor the daily variations in CIDs in the influent, effluent, and effluent-receiving river of a WWTP in Beijing over 1 week. The common occurrence of 1R,2S-(-)-ephedrine (1R,2S-(-)-EPH), 1S,2S-(+)-pseudoephedrine (1S,2S-(+)-PEPH), R-(-)-methamphetamine (METH), and S-(+)-METH in wastewater samples was observed. Ephedrines (1R,2S-(-)-EPH and 1S,2S-(+)-PEPH) were the most abundant CIDs in the influent, effluent, upstream, and downstream samples with concentrations of 725.8±181.2ng/L, 22.9±4.9ng/L, 12.96±0.79ng/L, and 11.6±6.7ng/L, respectively. METH was detectable in most water samples and was present in excess in S-enantiomer form in the influent and in R-enantiomer form in the effluent and surface water. R-(-)-MDMA was detected at a concentration of up to 2.4ng/L in the influent. The metabolites norketamine (NK), amphetamine(AMP), MDA, and NE were not detected in water samples given the low concentration of their parent drugs.

A fast GC-MS screening procedure for ketamine and its metabolites in urine samples

The rapid increase of ketamine abuse worldwide has created a need for a fast and efficient screening procedure. Currently, there is no commercially available immunoassay. We developed a simple extraction and GC/MS screening procedure to screen out negative samples. Urine samples (1 mL) were spiked with ketamine-d4 as internal standard. After liquid-liquid extraction, samples were screened for ketamine (K) and its two metabolites, norketamine (NK) and dehydronorketamine (DHNK), with GC/MS without derivatization. The total analytical time is 5 min for each sample. The detection limit for K, NK and DHNK was 10 ng/mL, 10 ng/mL and 30 ng/mL, respectively. The within-run precision and accuracy for 80, 160, 400 ng/mL of K, NK and DHNK were all between -12.50% and 8.17%. We collected 163 urine samples from disco-dancing clubs in Taiwan. Samples were screened and confirmed with GC/MS. The total analytical time for GC-MS confirmation is 20 min per sample. The sensitivity is 98.9% and specificity is 100%. This screening method is rapid, sensitive and applicable to forensic and clinical toxicological analyses.

Pharmacokinetic Effects of l-Tetrahydropalmatine on Ketamine in Rat Plasma by Ultraperformance Liquid Chromatography Tandem Mass Spectrometry.

Male Sprague-Dawley rats (n = 18) were randomly divided into three groups: a saline group (20 mL/kg by gavage), a ketamine (KET) group (100 mg/kg by gavage), and a KET (the same routes and doses) combined with levo-tetrahydropalmatine (l-THP; 40 mg/kg by gavage) group (n = 6). Blood samples were acquired at different time points after drug administration. A simple and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to determine the concentrations of KET and its metabolite, norketamine (NK), in rat plasma. Chromatographic separation was achieved using a BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with chlorpheniramine maleate (Chlor-Trimeton) as an internal standard (IS). The initial mobile phase consisted of acetonitrile–water with 0.1% methanoic acid (80 : 20, v/v). The multiple reaction monitoring (MRM) modes of m/z 238.1→m/z 179.1 for KET, m/z 224.1→m/z 207.1 for NK, and m/z 275→m/z 230 for Chlor-Trimeton (IS) were utilized to conduct a quantitative analysis. Calibration curves of KET and NK in rat plasma demonstrated good linearity in the range of 2.5–500 ng/mL (r > 0.9994), and the lower limit of quantification (LLOQ) was 2.5 ng/mL for both. Moreover, the intra- and interday precision relative standard deviation (RSD) of KET and NK were less than 4.31% and 6.53%, respectively. The accuracies (relative error) of KET and NK were below -1.41% and -6.07%, respectively. The extraction recoveries of KET and NK were more than 81.23 ± 3.45% and 80.42 ± 4.57%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to study the pharmacokinetic effects of l-THP on KET after gastric gavage. The results demonstrated that l-THP could increase the bioavailability of KET and promote the metabolism of KET. The results showed that l-THP has pharmacokinetics effects on KET in rat plasma.

Targeted mass spectrometry of ketamine and its metabolites cis-6-hydroxynorketamine and norketamine in human blood serum

Ketamine (KET) was originally developed as an anesthetic agent but has also attracted attention for further clinical applications such as medical treatment of depression or pain. The use of KET induces dissociation and emergence delirium. Due to these effects, KET has a high potential for abuse. In order to investigate metabolization of KET or to confirm misuse of KET, highly sensitive analytical methods that cover KET and its metabolites are necessary. A new analytical approach for simultaneous analysis of KET and its metabolites cis-6-hydroxynorketamine (HNK) and norketamine (NK) was established. The compounds were extracted from human blood serum by ultrafiltration and solid phase extraction with subsequent vacuum evaporation. The compounds were analyzed by non-enantioselective ultra-high performance micro-flow liquid chromatography (Waters ACQUITY UPLC® M-Class HSS T3 column, 0.1% formic acid and acetonitrile with 0.1% formic acid, 14 µL/min flow rate) coupled with tandem mass spectrometry in positive scheduled multiple reaction monitoring mode. Validation parameters such as linearity, precision, recovery, accuracy, stability, limit of detection (LOD), and limit of quantification (LOQ) were proven. LOD for KET and NK was 0.08 ng/mL and LOQ were 0.5 ng/mL and 0.6 ng/mL, respectively. For HNK, LOD was 0.1 ng/mL and LOQ 0.8 ng/mL. The method was then successfully applied to quantify KET, HNK, and NK in blood serum samples from subjects who received KET intravenously. A novel method for the simultaneous analysis of KET, NK, and HNK was established. This new method could now be used for clinical trials investigating KET and its metabolites HNK and NK or for forensic analysis in order to confirm KET abuse.

A Retrospective of Prevalence of Drugs of Abuse by Hair Analysis in Shanghai using LC-MS-MS.

This study presents a retrospective analysis of the prevalence of drug abuse in Shanghai by hair analysis. Files and toxicology analysis results of a total of 5,610 cases requesting for hair analysis of abused drugs at the Academy of Forensic Science (AFS) in Shanghai over 12months between August 2018 and July 2019 were reviewed. All cases of drug abuse identified by hair analysis were from the public security organs in Shanghai, China. Hair samples were analyzed for drugs of abuse and related metabolites, mainly including amphetamine (AMP), methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), tetrahydrocannabinol (THC), ketamine (K), norketamine (NK), cocaine (COC), benzoylecgonine, morphine, 6-acetylmorphine, flunitrazepam, and 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Among the 5,610 cases, 1,713 (30.5%) were positive for drugs of abuse, with amphetamine-type stimulants (ATS) (57%), including amphetamines (AMP and MA) (48%), MDMA and MDA (9%), being the most frequently detected drugs, followed by THC (14%), COC (8%), 5-MeO-DIPT (8%), and K (7%). The majority (75%) of positive hair samples were from male subjects. Overall, 77% of abusers were younger than 44years old. The proportion of female subjects (22.3%) under 24years was larger than that of male subjects (7.8%). There were 132 cases (7.7%) in which more than one type of drug was detected among 1,713 drug-positive cases. The most common combination was MDMA and K. The present study characterizes the current toxicological profile of drug abuse cases and provides a scientific basis for drug abuse prevention. Moreover, the hair concentration distributions of the commonly abused drugs in positive cases have been reported.

Environmental behavior of methamphetamine and ketamine in aquatic ecosystem: Degradation, bioaccumulation, distribution, and associated shift in toxicity and bacterial community

Ketamine (KET) and methamphetamine (METH) have been recognized as emerging contaminants in aquatic ecosystems. This paper aimed to investigate the environmental behaviour, including the degradation, distribution, and bioaccumulation, of METH, KET, and their main metabolites (amphetamine (AMP) and norketamine (NorKET)). The changes in acute toxicity in the aqueous phase and in the bacterial community in sediment were determined to assess the associated eco-risk of the drug exposure. Five types of lab-scale aquatic ecosystems were established and exposed to KET or METH for 40 days: a water- sediment- organisms- KET system (K), a water- sediment- organisms- METH system (M), a water- sediment- organism- METH- KET system (M + K), a water-sediment- KET- METH system (control), and a water- sediment- organisms system (biocontrol). The results demonstrated that much faster degradation occurred for both METH (t1/2 = 3.89 and 2.37 days in the M and M + K group, respectively) and KET(t1/2 = 5.69 days 5.39 days in the K group and M + K group, respectively) than in the control group (t1/2 = 7.83 and 86.71days for METH and KET, respectively). Rapid adsorption of KET, METH, and their metabolites was observed in the sediment, which had clay and silt as the main particle sizes. KET was observed to be absorbed by shallow-water fish (Chinese medaka, rosy bitterling and mosquito fish), while METH was dominantly ingested by bottom-dwellers (loach). Duckweed might play a crucial role in the dissipation process of METH and KET, which were mainly adsorbed by duckweed roots. During incubation, the acute toxic levels in the K and M + K groups changed from non-toxic to medium toxicity levels, and the toxicity in the M and control groups changed from non-toxic to low toxicity levels. Moreover, marked changes in the bacterial community in the sediment induced by METH or KET exposure were observed, and the most significant change in the bacterial community was observed in the group spiked with both METH and KET. This work for the first time elucidated the environmental behaviors of METH and KET in aquatic ecosystem and associated the impact on ecological system equilibrium.

Dexmedetomidine and ketamine simultaneous administration in tigers (Panthera tigris): pharmacokinetics and clinical effects.

BackgroundThe study determines the pharmacokinetic profiles of dexmedetomidine (DEX), ketamine (KET) and its active metabolite, norketamine (NORKET), after simultaneous administration. Moreover, the study evaluates the sedative effects of this protocol, its influence on the main physiological variables and the occurrence of adverse effects.MethodsEighteen captive tigers were initially administered with a mixture of DEX (10 µg/kg) and KET (2 mg/kg) by remote intramuscular injection. In case of individual and specific needs, the protocol was modified and tigers could receive general anaesthesia, propofol or additional doses of DEX and KET.ResultsBased on the immobilisation protocol, nine animals were assigned to the standard protocol group and the other nine to the non-standard protocol group. Higher area under the first moment curve (AUMC0-last) and longer mean residence time (MRT0-last) (P<0.05) were observed in the non-standard protocol group for DEX, KET and NORKET, and higher area under the concentration-time curve from administration to the last measurable concentration (AUC0-last) only for KET. The KET metabolisation rate was similar (P=0.296) between groups. No differences between groups were detected in terms of stages of sedation and recoveries. All physiological variables remained within normality ranges during the whole observation period. During the hospitalisation period, no severe adverse reactions and signs of resedation were observed.ConclusionThe simultaneous administration of 10 µg/kg of DEX and 2 mg/kg of KET can be considered an effective protocol for chemical immobilisation of captive tigers, along with dosage adjusments or when other drugs are needed.

Simultaneous quantitative LC–MS method of ketamine, midazolam and their metabolites (dehydronorketamine, norketamine and 1hydroxymidazolam) for its application in patients on extracorporeal membrane oxygenation (ECMO) therapy

Ketamine (Ket) and midazolam (MDZ) are commonly administered drugs in the intensive care setting for analgesia and sedation. Ket and MDZ are metabolized to dehydro-norketamine (DHNK), nor-ketamine (NK) and 1-hydroxy midazolam (1HMDZ). Limited studies evaluating their pharmacokinetics exists in patients on extracorporeal membrane oxygenation (ECMO) therapy. Therefore, we developed a quantitative, high-performance liquid chromatography-mass spectrometry (with single ion monitoring) method to simultaneously detect Ket, MDZ and their (DHNK, NK and 1HMDZ) metabolites in human plasma. Considerable sensitivity was obtained for the analytes using a C18 HILIC column operated by a high-performance liquid chromatography system coupled with a Thermo Exactive Orbitrap mass spectrometer. Calibration curves were developed for analyte molecules (n = 5) in the presence of carbamazepine (CBZ) as an internal standard. The lower limits of quantitation (LLOQ) for Ket and MDZ were 20 and 10 ng/mL, respectively with the LLOQ for DHNK, NK and 1HMDZ at 470, 320 and 150 ng/ml. Moreover, the percent coefficient of variance and precision for inter- and intra-day runs were within the standards set forth by the ICH and FDA guidelines. This method is sensitive and has been successfully applied to an ongoing pharmacokinetic study in patients on ECMO therapy.

Sex Differences in the Pharmacokinetics of Low-dose Ketamine in Plasma and Brain of Male and Female Rats.

Recent work from our group and others has revealed a higher sensitivity of female rodents to the antidepressant-like effects of the N-methyl d-aspartate receptor antagonist ketamine strongly influenced by circulating estrogen and progesterone levels. However, in the absence of any preclinical studies of pharmacokinetic sex differences using low-dose ketamine in rats, it is unclear whether the effects of sex and hormonal milieu on ketamine's behavioral actions are influenced by differences in ketamine metabolism between male and female rats. Therefore, this work examined whether sex and hormonal status affect ketamine metabolism and distribution in male and female rats using a low antidepressant-like dose selectively effective in females. Intact male rats and female rats in either diestrus (low estrogen, progesterone) or proestrus (high estrogen, progesterone) were administered low-dose ketamine, and their plasma and brains were collected to analyze levels of ketamine and its metabolites norketamine (NK) and dehydronorketamine. Females exhibited greater concentrations of ketamine and NK over the first 30 min following treatment in both brain and plasma, largely accounted for by slower clearance rates and longer half-lives. Interestingly, despite the impact of ovarian hormones on behavioral sensitivity to ketamine, no appreciable differences in pharmacokinetic parameters existed between proestrus and diestrus female rats. This work is the first to demonstrate sex differences in ketamine pharmacokinetics in rats, and suggests that while sex differences in metabolism may influence the amount of ketamine and NK reaching target areas in the brain, the impact of circulating hormone levels here is negligible.