Evaluation of ketamine abuse using hair analysis: concentration trends in a Singapore population

The duration of ketamine detection in hair after treatment cessation: Case study and review of the literature in forensic and clinical casework

The disappearance of drug from hair does not occur immediately after abstinence because dormant hair may contribute to the positivity of freshly grown hair. The aim of this study was to assess ketamine disappearance from hair after treatment cessation and to review the literature data. A 22-year-old female received three intravenous doses of ketamine (171 mg) for major depression treatment. Seventeen weeks later, a 26 cm lock of hair was sampled, and ketamine was determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) on seven segments: A (proximal, 0-2 cm), B (2-4 cm), C (4-6 cm, period of ketamine therapy), and D to G (4 × 5 cm). Ketamine concentration was 58 pg/mg in Segment C and remained detectable over 4 months after treatment cessation at 67 pg/mg in Segment B and 2 pg/mg in Segment A, representing a 97% drop from the initial concentration. Ketamine elimination half-life in hair was estimated at 0.88 month, implying that indetectable concentration should be expected 7 months after cessation. Axial diffusion was excluded as ketamine was not detected in Segments D-G. Given the low ketamine concentrations, norketamine was not detected. While no data on ketamine disappearance from hair have been published to date, previous studies have shown that discontinuation resulted in negative hair results after 3 months for heroin, 3-4 months for cocaine and tramadol, 6 months for amphetamine and methamphetamine, and 6-7 months for THC-COOH. This study provides useful findings for ketamine hair concentration interpretation, which should be validated by more consistent and comprehensive investigations.

Microextraction by Packed Sorbent as a Clean-up Approach for the Determination of Ketamine and Norketamine in Hair by Gas Chromatography--Tandem Mass Spectrometry

The use of new psychoactive substances has been increasing and constitutes a social and public health problem, and hence, toxicological analysis has become of utmost importance for the detection of such substances. In this article, we present the development and full validation of a simple, user and environmentally friendly, cheap and suitable method for the determination of ketamine and its main metabolite norketamine in hair samples. The procedure included using a miniaturized procedure-microextraction by packed sorbent with mixed-mode sorbent-for sample clean-up. Organic solvents use was minimal, and it was possible to obtain a linear method (0.05-10 ng/mg for both analytes). The extraction efficiency ranged from 32 to 61%, which did not impair sensitivity. The method proved to be selective, precise, accurate and suitable for routine analysis for the determination of said compounds in 50-mg hair samples.

Determination of Ketamine and Norketamine in Hair and Evaluation of Polydrug Use in Ketamine Abusers Using Hair Analysis in Korea

This study evaluated hair samples from 28 subjects who tested positive for ketamine at Seoul Institute National Forensic Service in Korea between 2016 and 2017. Ketamine in the hair was extracted using a solution of 1% hydrochloric acid in methanol for 16 h. Extracts were analyzed using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS-MS). The LC-MS-MS method was validated by determining the limit of detection (LOD), limit of quantification (LOQ), linearity, intra- and inter-accuracy, precision and matrix effect. In 59 ketamine-positive hair or hair segments from 28 ketamine abusers, the ketamine concentration was found to be in the range of 0.011-335.8 ng/mg (mean, 13.6; median, 1.8), and the norketamine concentration was found to be in the range of 0.001-35.7 ng/mg (mean, 7.5; median, 0.44). The ratio of norketamine to ketamine concentrations in hair was in the range of 0.01-1.46 (mean, 0.34; median, 0.26). The distribution of ketamine concentration in hair samples was as follows: 0.01-0.1 ng/mg in 11 samples (18.6%), 0.1-5 ng/mg in 33 samples (55.9%), 5-10 ng/mg in 4 samples (6.8%), 10-15 ng/mg in 2 samples (3.4%), 15-20 ng/mg in 4 samples (6.8%), 40-45 ng/mg in 2 samples (3.4%), 45-50 ng/mg in 1 sample (1.7%) and >100 ng/mg in only 2 samples (3.4%). In the hair of ketamine abusers, 26 of 28 subjects were detected simultaneously ketamine with other drugs, including methylenedioxymethamphetamine (MDMA; n = 9), methamphetamine (MA; n = 3), MDMA/MA (n = 3), MDMA/para-methoxyamphetamine (PMA; n = 3), MDMA/PMA/MA (n = 2), cocaine (n = 1) and other drugs (n = 5, propofol, zolpidem or benzodiazepines). Along with ketamine, other controlled drugs were detected in most of the hair samples: MDMA (60.7%), MA (28.6%), PMA (17.9%), zolpidem (17.9%) and propofol (14.3%) in the frequency of abuse. In conclusion, most of the ketamine abusers (92.9%) were polydrug abusers, who were concomitantly abusing other controlled substances.

A Systematic Review of Metabolite-to-Drug Ratios of Pharmaceuticals in Hair for Forensic Investigations

After ingestion, consumed drugs and their metabolites are incorporated into hair, which has a long detection window, ranging up to months. Therefore, in addition to conventional blood and urine analyses, hair analysis can provide useful information on long-term drug exposure. Meta-bolite-to-drug (MD) ratios are helpful in interpreting hair results, as they provide useful information on drug metabolism and can be used to distinguish drug use from external contamination, which is otherwise a limitation in hair analysis. Despite this, the MD ratios of a wide range of pharmaceuticals have scarcely been explored. This review aims to provide an overview of MD ratios in hair in a range of pharmaceuticals of interest to forensic toxicology, such as antipsychotic drugs, antidepressant drugs, benzodiazepines, common opiates/opioids, etc. The factors influencing the ratio were evaluated. MD ratios of 41 pharmaceuticals were reported from almost 100 studies. MD ratios below 1 were frequently reported, indicating higher concentrations of the parent pharmaceutical than of its metabolite in hair, but wide-ranging MD ratios of the majority of pharmaceuticals were found. Intra- and interindividual differences and compound properties were variables possibly contributing to this. This overview presents guidance for future comparison and evaluation of MD ratios of pharmaceuticals.

Prevalence of New Psychoactive Substances (NPS) and conventional drugs of abuse (DOA) in high risk populations from Paris (France) and its suburbs: A cross sectional study by hair testing (2012-2017)

BACKGROUND

The aim of the present study is to describe the prevalence of NPS and conventional DOA in Paris and its suburbs over a six-year period using hair testing approach.

METHOD

Hair was sampled in patients admitted to different departments of Paris hospitals between 2012 and 2017. Two high-risk populations were mainly considered: 1) drug-dependent and 2) acutely intoxicated patients. Segmental hair analysis was performed by validated LC-MS/MS method to screen for DOA and 83 NPS.

RESULTS

480 patients (280 M/200 F, 15-70 years) were included. 141 patients tested positive for NPS (99 M/42 F; median age: 33). NPS prevalence was 29%, that of amphetamines, cocaine and opioids were 32%, 38.5% and 52%, respectively. 27 NPS were identified, 4-MEC and mephedrone (number of cases n = 24 each) were the most detected cathinones. JWH-122 (n = 1) was the only detected synthetic cannabinoid while ketamine (n = 104) was present in numerous NPS users (67%). 3-fluorofentanyl (n = 1), furanylfentanyl (n = 1), N-ethylpentylone (n = 2), pentedrone (n = 2), mexedrone (n = 1), methcathinone (n = 3), 6-APDB (n = 2), TFMPP (n = 2), 2-CE (n = 1), 3,4-MD-αPHP (n = 1) and dextromethorphan (n = 27) were identified for the first time in hair. Users were found to have more than one NPS in 53% of cases, mostly in combination with conventional DOA. The number of detected NPS rose from 5 in 2012 to 42 in 2017. A broad range of hair concentrations (0.001-318 ng/mg) was found, but the low median concentrations seem to show an occasional exposure more than chronic use.

CONCLUSION

NPS screening should be assessed in routine clinical practice, especially in high-risk populations.

Simultaneous Quantitative Determination of Amphetamines, Opiates, Ketamine, Cocaine and Metabolites in Human Hair: Application to Forensic Cases of Drug Abuse

A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to simultaneously quantify amphetamines, opiates, ketamine, cocaine, and metabolites in human hair is described. Hair samples (50 mg) were extracted with methanol utilizing cryogenic grinding. Calibration curves for all the analytes were established in the concentration range 0.05-10 ng/mg. The recoveries were above 72%, except for AMP at the limit of quantification (LOQ), which was 48%. The accuracies were within ±20% at the LOQ (0.05 ng/mg) and between -11% and 13.3% at 0.3 and 9.5 ng/mg, respectively. The intraday and interday precisions were within 19.6% and 19.8%, respectively. A proficiency test was applied to the validated method with z-scores within ±2, demonstrating the accuracy of the method for the determination of drugs of abuse in the hair of individuals suspected of abusing drugs. The hair concentration ranges, means, and medians are summarized for abused drugs in 158 authentic cases.

Particle-size distribution (PSD) of pulverized hair: A quantitative approach of milling efficiency and its correlation with drug extraction efficiency

Different types of hair were submitted to different milling procedures and their resulting powders were analyzed by scanning electron microscopy (SEM) and laser diffraction (LD). SEM results were qualitative whereas LD results were quantitative and accurately characterized the hair powders through their particle size distribution (PSD). Different types of hair were submitted to an optimized milling conditions and their PSD was quite similar. A good correlation was obtained between PSD results and ketamine concentration in a hair sample analyzed by LC-MS/MS. Hair samples were frozen in liquid nitrogen for 5min and pulverized at 25Hz for 10min, resulting in 61% of particles <104μm and 39% from 104 to 1000μm. Doing so, a 359% increment on ketamine concentration was obtained for an authentic sample extracted after pulverization comparing with the same sample cut in 1mm fragments. When milling time was extended to 25min, >90% of particles were <60μm and an additional increment of 52.4% in ketamine content was obtained. PSD is a key feature on analysis of pulverized hair as it can affect the method recovery and reproducibility. In addition, PSD is an important issue on sample retesting and quality control procedures.

Brain metabolomics in rats after administration of ketamine

In this study, we developed a brain metabolomic method, based on gas chromatography-mass spectrometry (GC/MS), to evaluate the effect of ketamine on rats. Pattern recognition analysis, including both principal component analysis and partial least squares-discriminate analysis revealed that ketamine induced metabolic perturbations. Compared with the control group, the levels of glycerol, uridine, cholesterol in rat brain of the ketamine group (50 mg/kg, 14 days) decreased, while the urea levels increased. Our results indicate that metabolomic methods based on GC/MS may be useful to elucidate ketamine abuse through the exploration of biomarkers.

Glutamate receptor antagonists as fast-acting therapeutic alternatives for the treatment of depression: ketamine and other compounds

The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has rapid and potent antidepressant effects in treatment-resistant major depressive disorder and bipolar depression. These effects are in direct contrast to the more modest effects seen after weeks of treatment with classic monoaminergic antidepressants. Numerous open-label and case studies similarly validate ketamine's antidepressant properties. These clinical findings have been reverse-translated into preclinical models in an effort to elucidate ketamine's antidepressant mechanism of action, and three important targets have been identified: mammalian target of rapamycin (mTOR), eukaryotic elongation factor 2 (eEF2), and glycogen synthase kinase-3 (GSK-3). Current clinical and preclinical research is focused on (a) prolonging/maintaining ketamine's antidepressant effects, (b) developing more selective NMDA receptor antagonists free of ketamine's adverse effects, and (c) identifying predictor, mediator/moderator, and treatment response biomarkers of ketamine's antidepressant effects.

Infant with in utero ketamine exposure: quantitative measurement of residual dosage in hair

BACKGROUND

The drug ketamine is frequently abused for recreational use in Asia, but few studies in humans have focused on the effects of ketamine exposure during pregnancy on the health of neonates. Here, we report a neonate whose mother was suspected of ketamine abuse during pregnancy. The case was confirmed by testing hair samples of the neonate.

METHODS

Hair samples of the neonate were taken on the first day of referral. Levels of common drugs of abuse in Asia were measured in the hair sample by gas chromatography-mass spectrometry using our previously reported method with modifications. This method was developed and validated to simultaneously quantify levels of amphetamine, ketamine and opiate in human hair.

RESULTS

The neonate was a female baby, born full term, with a low birth weight of 2250 g. Very high levels of ketamine were detected in the neonate's hair, even though the mother stated that she had stopped abusing ketamine during the early stage of pregnancy. The neonate suffered from general hypotonia; moderate cerebral dysfunction was found by electroencephalography. Fortunately, her hypotonia improved gradually within 21 days.

CONCLUSION

This is the first report of ketamine exposure during late pregnancy detected by hair testing. We noted several clinical features in this case, including the infant being small for gestational age, intrauterine growth retardation, remarkable hypotonia, and poor reflex responses. Although the mother denied the use of ketamine during the late stage of her pregnancy, significant amount of ketamine and norketamine was still found in hair samples (only 2 cm long and 25 mg) from the infant.

Analytical methods for abused drugs in hair and their applications

Hair has been focused on for its usability as an alternative biological specimen to blood and urine for determining drugs of abuse in fields such as forensic and toxicological sciences because hair can be used to elucidate the long intake history of abused drugs compared with blood and urine. Hair analysis consists of several pretreatment steps, such as washing out contaminates from hair, extraction of target compounds from hair, and cleanup for instrumental analysis. Each step includes characteristic and independent features for the class of drugs, e.g., stimulants, narcotics, cannabis, and other medicaments. In this review, recently developed methods to determine drugs of abuse are summarized, and the pretreatment steps as well as the sensitivity and applicability are critically discussed.

Study of the fragmentation pattern of ketamine-heptafluorobutyramide by gas chromatography/electron ionization mass spectrometry

Ketamine is an anaesthetic compound used in human and veterinary medicine with hallucinogen properties that have resulted in its increased illicit use by teenagers at rave parties. Although several gas chromatography/mass spectrometry (GC/MS) methods have been reported for the quantification of the drug both in urine and in hair, its electron ionization (EI) fragmentation after derivatization with different reagents has been not yet fully investigated. The present work reports the study of the fragmentation of ketamine, derivatized with heptafluorobutyric anhydride (HFBA-Ket), using gas chromatography/electron ionization mass spectrometry (GC/EI-MS). The complete characterization of the fragmentation pattern represented an intriguing exercise and required tandem mass spectrometry (MS(n)) experiments, high-resolution accurate mass measurements and the use of deuterated d(4)-ketamine to corroborate the proposed structures and to characterize the fragment ions carrying the unchanged aromatic moiety. Extensive fragmentation was observed, mainly located at the cyclohexanone ring followed by rearrangement of the fragment ions, as confirmed by the mass spectra obtained from the deuterated molecule. The GC/EI-MS analysis of HFBA-Ket will represent a useful tool in forensic science since high-throughput analyses are enabled, preserving both the GC stationary phase and the cleanliness of the mass spectrometer ion optics.

Use of human microsomes and deuterated substrates: an alternative approach for the identification of novel metabolites of ketamine by mass spectrometry

In vitro biosynthesis using pooled human liver microsomes was applied to help identify in vivo metabolites of ketamine by liquid chromatography (LC)-tandem mass spectrometry. Microsomal synthesis produced dehydronorketamine, seven structural isomers of hydroxynorketamine, and at least five structural isomers of hydroxyketamine. To aid identification, stable isotopes of the metabolites were also produced from tetra-deuterated isotopes of ketamine or norketamine as substrates. Five metabolites (three hydroxynorketamine and two hydroxyketamine isomers) gave chromatographically resolved components with product ion spectra indicating the presence of a phenolic group, with phenolic metabolites being further substantiated by selective liquid-liquid extraction after adjustments to the pH. Two glucuronide conjugates of hydroxynorketamine were also identified. Analysis by LC-coupled ion cyclotron resonance mass spectrometry gave unique masses in accordance with the predicted elemental composition. The metabolites, including the phenols, were subsequently confirmed to be present in urine of subjects after oral ketamine administration, as facilitated by the addition of deuterated metabolites generated from the in vitro biosynthesis. To our knowledge, phenolic metabolites of ketamine, including an intact glucuronide conjugate, are here reported for the first time. The use of biologically synthesized deuterated material as an internal chromatographic and mass spectrometric marker is a viable approach to aid in the identification of metabolites. Metabolites that have particular diagnostic value can be selected as candidates for chemical synthesis of standards.

Analytical pitfalls in hair testing

This review focuses on possible pitfalls in hair testing procedures. Knowledge of such pitfalls is useful when developing and validating methods, since it can be used to avoid wrong results as well as wrong interpretations of correct results. In recent years, remarkable advances in sensitive and specific analytical techniques have enabled the analysis of drugs in alternative biological specimens such as hair. Modern analytical procedures for the determination of drugs in hair specimens - mainly by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) - are reviewed and critically discussed. Many tables containing information related to this topic are provided.

Gas chromatography-mass spectrometry analysis of ketamine and its metabolites--a comparative study on the utilization of different derivatization groups

Method of chemical derivatization is the main difference among the GC-MS based methodologies reported for the analysis of ketamine and its major metabolites (norketamine and dehydronorketamine). These approaches included acylation and silylation resulting in the formation of acetyl, trifluoroacetyl, heptafluorobutyryl, and pentafluorobenzoyl (for acylation); and possibly trimethylsilyl and t-butyldimethylsilyl (for silylation) derivatives. This study evaluates the merits of these approaches based on the following criteria: reaction yields and ionization efficiency of the derivatization products; chromatographic characteristics; and cross-contributions to the intensities of ions designating the analyte and the internal standard. Pentafluorobenzoyl-derivatives were found to provide the best performance characteristics.

Performance characteristics of ELISAs for monitoring ketamine exposure

BACKGROUND

Growing misuse of ketamine necessitates the development of high throughput testing approaches. Two commercial enzyme-linked immunosorbent assays (ELISA) for ketamine have recently become available and were adapted for this development.

METHOD

The newly available ketamine ELISA reagents were examined to better understand their cross-reacting, calibration and other performance characteristics. ELISA apparent analyte concentrations were also correlated against ketamine concentrations as determined by GC-MS to examine the relationship between these 2 parameters.

RESULT

Both adapting ketamine as the targeted analyte, reagent from International Diagnostic Systems (IDS) also responded very significantly to the metabolites of ketamine (norketamine and dehydronorketamine), while the NEOGEN reagent responded very specifically to ketamine.

CONCLUSION

NEOGEN ELISA test data exhibit better correlation with the ketamine concentration as determined by GC-MS. It can be more reliably used as the preliminary test method in the 2-step approach now routinely adapted in workplace drug testing programs. Using 100 ng/ml ketamine as the GC-MS cutoff, the corresponding ELISA cutoff value is approximately 110-120 ng/ml. With significantly higher responses to ketamine metabolites, IDS reagent can detect specimens with much lower ketamine/metabolites concentrations and can better meet other testing requirements.

Hair analysis for methamphetamine, ketamine, morphine and codeine by cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography

We established a capillary electrophoretic method with high sensitivity and specificity for testing hair taken from addicts. After pretreatment of hair sample, the cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI-Sweep-MEKC) was used to test for the presence of abused drugs in human hair. These drugs include morphine (M), codeine (C), ketamine (K) and methamphetamine (MA). First, an uncoated fused-silica capillary (40 cm, 50 microm I.D.) was filled with phosphate buffer (50 mM, pH 2.5) containing 30% methanol, followed by high conductivity buffer (100 mM phosphate, 6.9 kPa for 99.9 s). Electrokinetic injection (10 kV, 600 s) was used to load samples and to enhance sensitivity. Stacking steps and separations were performed at -20 kV with detection at 200 nm, using phosphate buffer (25 mM, pH 2.5) containing 20% methanol and 100 mM sodium dodecyl sulfate. Using CSEI-Sweep-MEKC, the analytes could be simultaneously analyzed and have a detection limit down to the level of picogram per milligram hair. During method validation, calibration plots were linear (r > or = 0.999) over a range of 0.15-80 ng/mg hair for MA and K, 0.3-30 ng/mg hair for C and 0.5-50 ng/mg hair for M. The limits of detection were 50 pg/mg hair for MA and K, 100 pg/mg hair for C and 200 pg/mg hair for M (S/N=3, sampling 600 s at 10 kV). Our method was applied for analysis of real hair samples taken from addicts. The addicts' specimens were also analyzed by LC-MS, and showed good coincidence of results. This method has proven feasible for application in detecting trace levels of abused drugs in forensic analysis.

Hair analysis for ketamine and its metabolites

A rapid and sensitive method was developed for the simultaneous identification and quantitation of ketamine (K) and its major metabolite, norketamine (NK) in hair. After decontamination, the hair sample was incubated and extracted, and analyzed by gas chromatography-mass spectrometry (GC-MS). Limits of quantitation were found to be 0.05 ng/mg. Hair segments in black color were collected from 15 K abusers. Based on an experiment with 15 cavies with black, white, and brown hair, the mechanism of incorporation of K into hair was investigated. After shaving hair on the back of the cavies (8 cm x 4 cm), they were separated into three groups and administered intraperitoneally once a day for 7 successive days with high, medium, and low doses of K, respectively. Two days after this, hair segments with different colors were shaved. There was a direct correlation between the concentration of K in cavy hair and the dose and DHNK was detected only in high dosage group. The concentration of K increased in the order of white, brown, and black hair. The possible factors responsible for the incorporation of K and its metabolites in hair were discussed.

New trends in hair analysis and scientific demands on validation and technical notes

This review focuses on basic aspects of method development and validation of hair testing procedures. Quality assurance is a major issue in drug testing in hair resulting in new recommendations, validation procedures and inter-laboratory comparisons. Furthermore recent trends in research concerning hair analysis are discussed, namely mechanisms of drug incorporation and retention, novel analytical procedures (especially ones using liquid chromatography-mass spectrometry (LC-MS) and alternative sample preparation techniques like solid-phase microextraction (SPME)), the determination of THC-COOH in hair samples, hair testing in drug-facilitated crimes, enantioselective hair testing procedures and the importance of hair analysis in clinical trials. Hair testing in analytical toxicology is still an area in need of further research.