Intoxication caused by new psychostimulants: analytical methods to disclose acute and chronic use of benzofurans and ethylphenidate

Alpha-methyltryptamine and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) fatal co-intoxication: case report and review of literature

The scientific literature contains little reliable data regarding new psychoactive substances and designer drugs, making it difficult to assess toxic blood levels and potentially lethal threshold. Here, we report a fatal co-intoxication involving two uncommon drugs ‒ alpha-methyltryptamine (AMT) and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) ‒ combined with exposure to benzodiazepines, ephedrine, and norephedrine. AMT and 5-MAPB were quantified using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC/MS-MS), revealing concentrations of AMT 4690 ng/mL and 5-MAPB 101 ng/mL in postmortem peripheral blood. We additionally reviewed the literature to help interpret the likely roles of these molecules in the occurrence of death.

Toxicological investigations in a death involving 2-MAPB

New psychoactive substances are becoming increasingly popular. However, there is a lack of mass spectral information on parent substances and their corresponding metabolites as well as fatal concentrations in body liquids and tissues. Only very few clinical reports and user reports exist. This is also the case for methylaminopropylbenzofuran (MAPB) isomers. Urine from a decedent was screened using different immuno assays, gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-high resolution mass spectrometry (LC-HRMS/MS). Additionally, respective targets were quantitated in all analyzed specimens by LC-MS/MS. Gas chromatography-infrared spectroscopy (GC-IR) was applied to confirm the identity of the intoxication. GC-MS and the amphetamine immuno assay were useful to track the putative intoxication. However, the chemical structure of 2-MAPB was only elucidated by means of LC-HRMS/MS and GC-IR. 2-MAPB was highest in urine (167 µg/mL), followed by gastric content (98.9 µg/mL), bile fluid (30.8 µg/mL), liver (22.2 µg/g), heart blood (16.7 µg/mL), and lowest in femoral blood (7.3 µg/mL). Besides the parent substance, we detected N-demethyl-2-MAPB and hydroxy-2-MAPB in the urine sample. This case report presents an intoxication caused by 2-MAPB. The 2-MAPB concentration found in femoral blood exceeded those reviewed for 5/6-MAPB. The concentrations of the other specimens cannot be evaluated because there exist no comparative data. The values presented can be applied to assess 2-MAPB intoxications in the future.

Simultaneous Determination of 5- and 6-APB in Blood, other Body Fluids, Hair, and Various Tissues by HPLC-MS/MS

5-(2-aminopropyl)benzofuran (5-APB) and 6-(2-aminopropyl)benzofuran (6-APB) are benzofuran analogues of amphetamine and belong to the category of new psychoactive substances (NPS). Despite already published fatal 5- and 6-APB intoxication - in most cases, a combination of both substances - no sensitive method for the simultaneous detection and quantification of these new psychoactive compounds in human blood samples has yet been developed. Therefore, an easy and fast sample preparation-, as well as specific high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) method for the determination of both substances in blood, were established and validated. In a fatal intoxication in 2017 at the Institute of Forensic and Traffic Medicine in Heidelberg, Germany, concentrations of 850 ng/mL (5-APB) and 300 ng/mL (6-APB) were determined in peripheral blood. Besides, other body fluids (central blood, urine, bile), hair, and various tissues were examined to verify the presence of both compounds and to gain first insights into their distribution. In this publication, we show a method for the simultaneous determination of 5- and 6-APB in human samples by a chromatographic method and to investigate their distribution in the human body.

The Psychonauts' World of Cognitive Enhancers

BACKGROUND

There is growing availability of novel psychoactive substances (NPS), including cognitive enhancers (CEs) which can be used in the treatment of certain mental health disorders. While treating cognitive deficit symptoms in neuropsychiatric or neurodegenerative disorders using CEs might have significant benefits for patients, the increasing recreational use of these substances by healthy individuals raises many clinical, medico-legal, and ethical issues. Moreover, it has become very challenging for clinicians to keep up-to-date with CEs currently available as comprehensive official lists do not exist.

METHODS

Using a web crawler (NPSfinder®), the present study aimed at assessing psychonaut fora/platforms to better understand the online situation regarding CEs. We compared NPSfinder® entries with those from the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and from the United Nations Office on Drugs and Crime (UNODC) NPS databases up to spring 2019. Any substance that was identified by NPSfinder® was considered a CE if it was either described as having nootropic abilities by psychonauts or if it was listed among the known CEs by Froestl and colleagues.

RESULTS

A total of 142 unique CEs were identified by NPSfinder®. They were divided into 10 categories, including plants/herbs/products (29%), prescribed drugs (17%), image and performance enhancing drugs (IPEDs) (15%), psychostimulants (15%), miscellaneous (8%), Phenethylamines (6%), GABAergic drugs (5%), cannabimimetic (4%), tryptamines derivatives (0.5%), and piperazine derivatives (0.5%). A total of 105 chemically different substances were uniquely identified by NPSfinder®. Only one CE was uniquely identified by the EMCDDA; no CE was uniquely identified by the UNODC.

CONCLUSIONS

These results show that NPSfinder® is helpful as part of an Early Warning System, which could update clinicians with the growing numbers and types of nootropics in the increasingly difficult-to-follow internet world. Improving clinicians' knowledge of NPS could promote more effective prevention and harm reduction measures in clinical settings.

Syntheses and analytical characterizations of novel (2-aminopropyl)benzo[b]thiophene (APBT) based stimulants

Two groups of amphetamine-like drugs with psychostimulant properties that were first developed during the course of scientific studies and later emerged as new psychoactive substances (NPS) are based on the (2-aminopropyl)indole (API) and (2-aminopropyl)benzofuran (APB) structural scaffolds. However, sulfur-based analogs with a benzo[b]thiophene structure (resulting in (2-aminopropyl)benzo[b]thiophene (APBT) derivatives) have received little attention. In the present investigation, all six racemic APBT positional isomers were synthesized in an effort to understand their structure-activity relationships relative to API- and APB-based drugs. One lesson learned from the NPS phenomenon is that one cannot exclude the appearance of such substances on the market. Therefore, an in-depth analytical characterization was performed, including various single- and tandem mass spectrometry (MS) and ionization platforms coupled to gas chromatography (GC) and liquid chromatography (LC), nuclear magnetic resonance spectroscopy (NMR), and solid phase and GC condensed phase infrared spectroscopy (GC-sIR). Various derivatizations have also been explored; it was found that all six APBT isomers could be differentiated during GC analysis after derivatization with heptafluorobutyric anhydride and ethyl chloroformate (or heptafluorobutyric anhydride and acetic anhydride) under non-routine conditions. Discriminating analytical features can also be derived from NMR, GC-EI/CI- single- and tandem mass spectrometry, LC (pentafluorophenyl stationary phase), and various infrared spectroscopy approaches (including GC-sIR). Availability of detailed analytical data obtained from these novel APBT-type stimulants may be useful to researchers and scientists in cases where forensic and clinical investigations are warranted.

New Psychoactive Substances: A Matter of Time

In the last few years, a wide range of new psychoactive substances (NPS) have been produced and marketed to elude the controlled substance lists. These molecules enter the traditional illegal and web market with poor knowledge about their toxicity, mechanism of action, metabolism, abuse potential so that they are directly tested by the consumers. This perspective highlights the main issues connected with NPS: the celerity they enter and leave the market once included in the banning laws to be substituted by new legal analogues; the unavailability of analytical screening tests and certified standards to perform toxicological analyses; the time lag between NPS identification and inclusion in the controlled substances lists. Finally, the authors take a snapshot of the commitment of the Italian Early Warning System in highlighting the recent seizures of NPS as well as the distribution of NPS related intoxication and deaths as an example of what is happening in the European countries and internationally.

Emerging club drugs: 5-(2-aminopropyl)benzofuran (5-APB) is more toxic than its isomer 6-(2-aminopropyl)benzofuran (6-APB) in hepatocyte cellular models

New phenylethylamine derivatives are among the most commonly abused new psychoactive substances. They are synthesized and marketed in lieu of classical amphetaminic stimulants, with no previous safety testing. Our study aimed to determine the in vitro hepatotoxicity of two benzofurans [6-(2-aminopropyl)benzofuran (6-APB) and 5-(2-aminopropyl)benzofuran (5-APB)] that have been misused as 'legal highs'. Cellular viability was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay, following 24-h drug exposure of human hepatoma HepaRG cells (EC₅₀ 2.62 mM 5-APB; 6.02 mM 6-APB), HepG2 cells (EC₅₀ 3.79 mM 5-APB; 8.18 mM 6-APB) and primary rat hepatocytes (EC₅₀ 964 μM 5-APB; 1.94 mM 6-APB). Co-incubation of primary hepatocytes, the most sensitive in vitro model, with CYP450 inhibitors revealed a role of metabolism, in particular by CYP3A4, in the toxic effects of both benzofurans. Also, 6-APB and 5-APB concentration-dependently enhanced oxidative stress (significantly increased reactive species and oxidized glutathione, and decreased reduced glutathione levels) and unsettled mitochondrial homeostasis, with disruption of mitochondrial membrane potential and decline of intracellular ATP. Evaluation of cell death mechanisms showed increased caspase-8, -9, and -3 activation, and nuclear morphological changes consistent with apoptosis; at concentrations higher than 2 mM, however, necrosis prevailed. Concentration-dependent formation of acidic vesicular organelles typical of autophagy was also observed for both drugs. Overall, 5-APB displayed higher hepatotoxicity than its 6-isomer. Our findings provide new insights into the potential hepatotoxicity of these so-called 'safe drugs' and highlight the putative risks associated with their use as psychostimulants.

Death following consumption of MDAI and 5-EAPB

5-(2-ethylaminopropyl)benzofuran (5-EAPB) and 5,6-methylenedioxy-2-aminoindane (MDAI) are two new psychoactive substances (NPS) exhibiting MDMA-like properties. In this paper, we report the case of a 28-years old man, known as drug addict, found dead at home, with two unidentified powders next to him. External examination by the forensic pathologist was unremarkable but no autopsy was performed. Powders, blood and urine (which were the only samples available) were submitted to general unknown screening by high pressure liquid chromatography with a diode array detector (HPLC-DAD) and ultra high pressure liquid chromatography with a time-of-flight detector (UPLC-TOF-MS), after liquid-liquid extraction for biological samples, or simple dilution for powders. Analysis revealed 68% of MDAI in one powder and 87% of 5-EAPB in the other one. Significant levels of the same substances were found in blood (MDAI: 2.09 mg/L and 5-EAPB: 6.45 mg/L). The cause of death was therefore attributed to the consumption of these NPS since screening for other drugs of abuse and for alcohol was negative (oxazepam was found in urine only). 5-methylaminopropylbenzofuran (5-MAPB) and 5-aminopropylbenzofuran (5-APB) were also found in blood (0.089 and 0.546 mg/L, respectively) and urine (1.00 and 4.88 mg/L, respectively). In addition to the inherent complexity of NPS identification by itself, another analytical difficulty in this case was the identification of the EAPB positional isomer. Our routine screening methods were not able to distinguish the positional isomer, but an additional classical gas chromatography technique was able to make the distinction. Anyway, in our case, this issue was simplified thanks to the availability of a relatively pure powder that was analyzed by nuclear magnetic resonance (NMR).

Benzo fury: A new trend in the drug misuse scene

Benzofurans, also known by users as benzo fury or benzofury, are synthetic phenethylamines and constitute the third most prominent group of new psychoactive substances (NPS). As the use of these substances has been spread as an alternative to the classic illicit psychostimulants, such as amphetamines, their legal status was reviewed, resulting in an utter prohibition of these NPS in many countries worldwide. Herein, the prevalence of abuse, chemistry, biological effects, metabolism, and the potential harms and risky behaviors associated with the abuse of benzofurans are reviewed. The congeners of this group are mainly consumed recreationally at electronic dance music parties, in polydrug abuse settings. Benzofurans preferentially act by disturbing the functioning of serotonergic circuits, which induces their entactogenic and stimulant effects and is the reason behind the considerable number of recent benzo fury-related deaths. The slight interaction of these drugs with the dopaminergic system justifies the rewarding effects of these drugs. To date, published evidence on the mechanisms of toxicity of benzo fury is very limited but a body of research is now beginning to emerge revealing an alarming public health threat regarding the abuse of these NPS.

Screening methods for rapid determination of new psychoactive substances (NPS) in conventional and non-conventional biological matrices

In the last years, a global awareness has arisen from the reported harmful effects and public health risks associated with the consumption of new psychoactive substances (NPSs). Improving efforts in the detection and identification of these substances have emerged as a global analytical challenge involving the large range of NPSs' chemical structures and the variety of conventional and non-conventional biological matrices. Indeed, detection capabilities and screening tools impact many fields and settings, including seized products analysis, workplace and roadside drug controls, emergency rooms, drug addiction treatment clinics, post-mortem and criminal caseworks, law enforcement and health interventions. Colorimetric, immunochemical and chromatographic-mass spectrometry techniques have been investigated and developed for the rapid identification of NPSs. Considering the continuous emergence of new substances, this review offers a panoramic view on the current status of analytical approaches for the rapid screening of NPSs, including, when available, data on conventional and non-conventional biological matrices. Although some of the presented methods are sound and promising, their applications are still limited, thus proving the importance of further investigations. New screening and sensitive targeted methods for NPS and their metabolites should be developed in different types of biological matrices, where concentration of substances and matrix effects can be significantly different.

2,4-Diamino-N10-methylpteroic acid (DAMPA) crystalluria in a patient with osteosarcoma treated with carboxypeptidase-G2 rescue after high-dose methotrexate-induced nephrotoxicity

BACKGROUND

High-dose methotrexate (HDMTX) therapy is a key component of many chemotherapy protocols. However, some patients develop HDMTX-induced nephrotoxicity. Carboxypeptidase-G2 (CPDG2) hydrolyses MTX into 2,4-diamino-N10-methylpteroic acid (DAMPA) and glutamic acid, and is used as a rescue agent in patients with nephrotoxicity and delayed elimination. Despite the frequency of HDMTX-induced renal injury, crystalluria is uncommon. Furthermore, crystals are rarely identified by conventional chemical methods.

OBJECTIVE

To determine the composition of crystalluria in a patient with osteosarcoma who was treated with CPDG2.

METHODS

Crystalluria was evaluated by optical microscopy, and chemical identification was performed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and Orbitrap™ high-resolution mass spectrometry (HRMS).

RESULTS

The HRMS spectra of the patient's urine sediment showed a main peak at m/z 326.13, corresponding to the molecular mass of DAMPA [(C₁₅H₁₅O₂N₇) + H⁺]. The FT-IR spectral patterns of the sediment and DAMPA were not identical. SEM was unable to identify the crystal.

CONCLUSION

DAMPA crystalluria was identified by Orbitrap™ HRMS in a patient treated with CPDG2 after HDMTX nephrotoxicity. This case reinforces the need to implement adequate measures to prevent nephrotoxicity. In cases of HDMTX-induced nephrotoxicity, urine sediment analysis should be requested.

A fatal blood concentration of 5-APB

For the new psychoactive drug 5-(2-aminopropyl) benzofuran (5-APB), very limited knowledge is available regarding lethal concentrations. We present a case and report the post mortem blood concentration of a fatal outcome for a 25 year old man related to the consumption of 5-APB. After intake, he became unconscious and stopped breathing. Cardiopulmonary resuscitation was started without success. After 30min he was declared dead at the scene. During autopsy, whole blood from the femoral vein was collected and screened for a wide range of medicinal drugs and drugs of abuse. 5-APB was initially identified by ultra high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) and subsequently confirmed by using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The only toxicological findings were ethanol 0.6g/L, tetrahydrocannabinol (THC) 0.0024mg/L and 5-APB 0.86mg/L. The cause of death was attributed to intake of 5-APB. Only one previous report of a fatal 5-APB concentration as the main toxicological agent exist in the literature, and the present concentration indicated that 5-APB could be lethal in lower concentrations than previously reported.

L- and D-threo ethylphenidate concentrations, pharmacokinetics, and pharmacodynamics in horses

Ethylphenidate is a psychostimulant and analog of the commonly prescribed compound, methylphenidate (Ritalin®). There are a limited number of studies describing the disposition and pharmacologic/toxicological effects of ethylphenidate in any species. The abuse potential in equine athletes along with the limited data available regarding administration in horses necessitates further study. The objectives of the current study were to describe drug concentrations, develop an analytical method that could be used to regulate its use, and describe the pharmacodynamic effects of ethylphenidate in horses. To that end, 12 horses were randomized into 3 dose groups (intravenous: 10 mg or 40 mg, oral: 40 mg). Ethylphenidate was administered and blood and urine samples were collected prior to and for up to 72 hours post drug administration. Concentrations of D-threo ethylphenidate and the metabolite ritalinic acid were measured using Liquid Chromatography-tandem Mass Spectrometry. L-threo ethylphenidate concentrations were estimated from D-threo ethylphenidate concentrations. Serum concentrations of ethylphenidate were below detectable levels by 8, 18, and 12 hours following intravenous administration of 10 mg and 40 mg and oral administration of 40 mg, respectively. Ritalinic acid was non-detectable at 72 hours in the group that received a 10-mg intravenous and 40-mg oral dose of ethylphenidate. Ritalinic acid concentrations were below the LOQ at 72 hours following intravenous administration of 40 mg of ethylphenidate. While the number of animals per dose group were small, no stimulatory behavior or significant changes in heart rate were noted. Untoward effects including gastrointestinal adverse effects were noted in all dose groups.

Toxicokinetics of NPS: Update 2017

This summarizing and descriptive review article is an update on previously published reviews. It covers English-written and PubMed-listed review articles and original studies published between May 2016 and November 2017 on the toxicokinetics of new psychoactive substances (NPS). Compounds covered include stimulants and entactogens, synthetic cannabinoids, tryptamines, phenethylamine and phencyclidine-like drugs, benzodiazepines, and opioids. First, an overview and discussion is provided on selected review articles followed by an overview and discussion on selected original studies. Both sections are then concluded by an opinion on these latest developments. The present review shows that the NPS market is still highly dynamic and that studies regarding their toxicokinetics are necessary to understand risks associated with their consumption. Data collection and studies are encouraged to allow for detection of NPS in biological matrices in cases of acute intoxications or chronic consumption. Although some data are available, scientific papers dealing with the mechanistic reasons behind acute and chronic toxicity are still lacking.

Cross-reactivity of selected benzofurans with commercial amphetamine and ecstasy immunoassays in urine

Aim: The aim of this study was to perform a cross-reactivity investigation of six benzofurans with immunoassays (IAs) screening tests for amphetamines and ecstasy in urine samples. Methods: The following benzofuranes were investigated: 5-(2-Methylaminopropyl)Benzofuran (5-MAPB), 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB), 5-(2-Aminopropyl)-Benzofuran (5-APB), 5-(2-Aminopropyl)-2,3-dihydrobenzofuran (5-APDB), 5-(2-Ethylaminopropyl)Benzofuran (5-EAPB) and 5-(2-Aminoethyl)-2,3-dihydrobenzofuran (5-AEDB). The study was performed with urine-free spiked samples and authentic urine samples using eight different IAs for amphetamines and ecstasy. Results: All evaluated benzofurans showed cross-reactivity in some of the IAs tested, except for 5-AEDB. Urine samples of an intoxication case involving 5-MAPB, 5-APB and 5-EAPB were also positives in the IAs tested. Conclusion: There is an important variability in the cross-reactivity of the IAs for amphetamine and ecstasy caused by benzofurans depending on the immunoassay employed and the tested compounds.