Blood concentrations of synthetic cathinones

First-Generation Synthetic Cathinones Produce Arrhythmia in Zebrafish Eleutheroembryos: A New Approach Methodology for New Psychoactive Substances Cardiotoxicity Evaluation

The increasing number of new psychoactive substances (NPS) entering the illicit drug market, especially synthetic cathinones, as well as the risk of cardiovascular complications, is intensifying the need to quickly assess their cardiotoxic potential. The present study aims to evaluate the cardiovascular toxicity and lethality induced by first-generation synthetic cathinones (mephedrone, methylone, and MDPV) and more classical psychostimulants (cocaine and MDMA) in zebrafish embryos using a new approach methodology (NAM). Zebrafish embryos at 4 dpf were exposed to the test drugs for 24 h to identify drug lethality. Drug-induced effects on ventricular and atrial heart rate after 2 h exposure were evaluated, and video recordings were properly analyzed. All illicit drugs displayed similar 24 h LC50 values. Our results indicate that all drugs are able to induce bradycardia, arrhythmia, and atrial-ventricular block (AV block), signs of QT interval prolongation. However, only MDPV induced a different rhythmicity change depending on the chamber and was the most potent bradycardia and AV block-inducing drug compared to the other tested compounds. In summary, our results strongly suggest that the NAM presented in this study can be used for screening NPS for their cardiotoxic effect and especially for their ability to prolong the QT intervals.

Synthetic Cathinones and Neurotoxicity Risks: A Systematic Review

According to the EU Early Warning System (EWS), synthetic cathinones (SCs) are the second largest new psychoactive substances (NPS) class, with 162 synthetic cathinones monitored by the EU EWS. They have a similar structure to cathinone, principally found in Catha Edulis; they have a phenethylamine related structure but also exhibit amphetamine-like stimulant effects. Illegal laboratories regularly develop new substances and place them on the market. For this reason, during the last decade this class of substances has presented a great challenge for public health and forensic toxicologists. Acting on different systems and with various mechanisms of action, the spectrum of side effects caused by the intake of these drugs of abuse is very broad. To date, most studies have focused on the substances’ cardiac effects, and very few on their associated neurotoxicity. Specifically, synthetic cathinones appear to be involved in different neurological events, including increased alertness, mild agitation, severe psychosis, hyperthermia and death. A systematic literature search in PubMed and Scopus databases according to PRISMA guidelines was performed. A total of 515 studies published from 2005 to 2022 (350 articles from PubMed and 165 from Scopus) were initially screened for eligibility. The papers excluded, according to the criteria described in the Method Section (n = 401) and after full text analyses (n = 82), were 483 in total. The remaining 76 were included in the present review, as they met fully the inclusion criteria. The present work provides a comprehensive review on neurotoxic mechanisms of synthetic cathinones highlighting intoxication cases and fatalities in humans, as well as the toxic effects on animals (in particular rats, mice and zebrafish larvae). The reviewed studies showed brain-related adverse effects, including encephalopathy, coma and convulsions, and sympathomimetic and hallucinogenic toxidromes, together with the risk of developing excited/agitated delirium syndrome and serotonin syndrome.

Toxicological Analysis of Cases of Mixed Poisonings with Synthetic Cathinones and Other Drugs of Abuse

Some of the most commonly used new psychoactive substances (NPSs) are synthetic cathinones (SCs). The literature increasingly indicates that SCs have a significant addictive potential and pose a high risk to human health and life. The vast majority of SC users take a number of substances simultaneously. This article lists the detected concentrations in 26 fatal and 2 non-fatal real cases, in which SCs or an SC along with other substances were determined in blood and other biological materials. The following SCs were found most often: α-pyrrolidinohexiophenone, α-pyrrolidinopentiophenone, N-ethylpentedrone (NEP), 4-methyl-α-ethylaminopentiophenone and N-ethylhexedrone. In addition to detected SCs, the analyzed samples showed the presence of conventional drugs such as methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, amphetamine and NPSs from groups other than SCs, such as synthetic cannabinoids (UR-144 and 5F-AMB), synthetic opioids (AH-7921, U-47700 and 4-fluorobutyrfentanyl) and others (desoxypipradrol and etizolam). The quantitative analyses were carried out by liquid chromatography with tandem mass spectrometry (LC-MS-MS). This study presents pioneering data on concentrations and effects of 4-ethylmethcathinone, NEP, N-ethylbuphedrone and mexedrone. Also noteworthy are the data on SCs that until now have rarely been described in the literature together with specified blood concentrations. The analyzed cases of taking SCs were associated with fatal intoxication (n = 26), driving under the influence of drugs (n = 2) and death caused by beating (n = 1). Taking SCs has serious side effects that can lead to multiple organ failure and death. The use of more than one psychoactive substance simultaneously (including at least one SC) contributes to increased SC toxicity. These data could be valuable for further interpretation of other results from toxicological analyses.

Synthetic Cathinones in Belgium: Two Case Reports with Different Outcomes Observed in the Emergency Room

We herein report two cases of cathinone intoxication. The first case is about a drug addict who was admitted to the emergency room after the injection of an unknown compound. He presented with tachycardia, palpitations, mydriasis, dyspnea, dizziness, headache and nausea. After leaving the hospital against medical advice, he returned the next day with police escort, presenting aggressiveness and agitation signs. One month later, he returned one more time for sleeping disorders, hallucinations and anxiety. He was finally transferred for his 21st detoxification treatment. The second case concerns a man who was wandering the streets and tried to escape when police officers called him. He confessed to snorting of N-ethylpentedrone and was admitted with severe agitation including delusion of persecution, tachycardia, mydriasis and fever. Because of renal failure, rhabdomyolysis and metabolic acidosis, he was transferred to the intensive care unit where he manifested worsening of the symptoms, turning into coma. He was intubated for 3 days before a complete resolution of the symptoms. A screening was performed by high-resolution mass spectrometry followed by quantifications made by high-performance liquid chromatography coupled with a diode array detector. In the first case, alpha-pyrrolidinohexiophenone was identified only during the first two admissions. However, as plenty of other psychotropic substances were also found, the cathinone alone could not be held directly responsible for the symptoms. In the second case, more than 2,000 ng/mL of N-ethylpentedrone was found without any decrease in the next 17 h, underlining the long half-life of this compound. Unlike the first case, symptoms could be clearly attributed to the cathinone. In conclusion, cathinones can be found on the Belgian illicit drug market, with various routes of administration and clinical consequences. In these two case reports, some common points were observed initially. However, one patient was finally able to leave the hospital without any treatment, whereas the other would most likely have died without intensive care.

A fatal case involving the highest ever reported 4-CMC concentration

Synthetic cathinones comprise a large amount of substances present on the dark market, which creates an undeniably worldwide problem and still is posing a threat. A 22-year-old man was brought to the Emergency Room from a party, where he had ingested orally 20 g of mephedrone. The man exhibited a disorder of consciousness with no logical verbal contact and dilated pupils. Moreover, a metabolic acidosis was present. The patient died after an hour from an admission to the ER. Blood and vitreous humor collected during an autopsy were analyzed with the use of an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-QqQ-MS/MS) with the use of C18 column in multiple reaction monitoring (MRM) mode. Both biological specimens were prepared using liquid-liquid extraction (LLE) with the use of ethyl acetate and 0.5 M ammonium carbonate water solution (pH 9). The limit of quantification (LOQ) of the method was 0.5 ng/ml in both matrices; precision and accuracy values did not exceed ±15%. Recovery of the method was in the range of 86.1%-102.7%. Determined concentrations of 4-CMC were 8542 and 9874 ng/ml in blood and vitreous humor, respectively. Other substances present in both biological materials were: atropine, diazepam, lidocaine, and its metabolite norlidocaine, as well as methcathinone and ethyl alcohol. The concentration presented in here described case is the highest ever reported 4-CMC concentration. Important aspect is also receiving other NPS by recreational users than intended, which lead to accidental poisoning (in presented case user assumed 4-CMC was 4-MMC).

Influence of long-term storage temperatures and sodium fluoride preservation on the stability of synthetic cathinones and dihydro-metabolites in human whole blood

PURPOSE

Synthetic cathinones, one of the largest groups of new psychoactive substances, represent a large analytical and interpretative challenge in forensic laboratories. Of these is the synthetic cathinones' instability in different biological samples, which may lead to drug concentration discrepancies when interpreting toxicological findings. In this study, the stability of a panel of synthetic cathinones and their dihydro-metabolites (n = 26) together with internal standard was monitored in human whole blood stored at various temperatures over 6 months. The influence of sodium fluoride as a preservative in blood collection tubes was also investigated.

METHODS

Samples were extracted using a two-step liquid-liquid extraction technique, and analyzed using a validated liquid chromatography-tandem mass spectrometry method following recommendations of published guidelines.

RESULTS

The influence of temperature over analytes' stability was an important element in whole blood samples, with - 40 °C being the best storage temperature for all tested analytes. Sodium fluoride did not significantly affect the stability of cathinones except at room temperature. Dihydro-metabolites displayed better stability in whole blood samples and remained detectable for a longer period of time under all tested conditions.

CONCLUSIONS

The data suggest that samples containing synthetic cathinones should be analyzed immediately, if possible. Alternatively, whole blood samples should be stored frozen (at - 40 °C or lower); however, (quantitative) results should be interpreted with caution after long-term storage. The data also promote the use of dihydro-metabolites as biomarkers for synthetic cathinones intake, as these reduced metabolites may be detected for longer period of time when compared with parent drugs in whole blood samples.

4'-Iodo-α-Pyrrolidinononanophenone Provokes Differentiated SH-SY5Y Cell Apoptosis Through Downregulating Nitric Oxide Production and Bcl-2 Expression

Abuse of pyrrolidinophenone derivatives (PPs) is known to cause severe damage to the central nervous system due to their high lipophilicity. In this study, we compared sensitivity to toxicity elicited by 4'-iodo-α-pyrrolidinononanophenone (I-α-PNP), one of the most potent cytotoxic derivatives among PPs synthesized previously, between SH-SY5Y cells differentiated by all-trans-retinoic acid (ATRA) and the undifferentiated cells, and found that the differentiated cells are more sensitive to I-α-PNP toxicity than the undifferentiated cells. Treatment with I-α-PNP elicited some apoptotic alterations (Bax expression, loss of mitrochondrial membrane potential, and activation of caspases) in the differentiated cells, whose patterns were similar to those in the undifferentiated cells. I-α-PNP treatment resulted in no significant alteration in Bcl-2 expression in the undifferentiated cells, whereas it considerably downregulated the protein expression in the differentiated cells, suggesting that the high I-α-PNP sensitivity of the differentiated cells is mainly due to downregulation of Bcl-2 expression. I-α-PNP treatment decreased nitric oxide (NO) production and neuronal NOS (nNOS) expression in the differentiated cells, and the patterns of I-α-PNP-evoked alterations in phosphorylation of cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) expression were almost the same as that in nNOS expression. Additionally, the addition of an NO donor restored the I-α-PNP-evoked alterations in expressions of Bcl-2, BDNF, and nNOS in the differentiated cells. These findings suggest that the downregulation of Bcl-2 expression by I-α-PNP in differentiated cells is attributed to the acceleration of two negative feedback loops (nNOS/NO/CREB loop and CREB/BDNF loop) triggered by decreased NO production.

Development of a New LC-MS/MS Screening Method for Detection of 120 NPS and 43 Drugs in Blood

In the last few years, liquid chromatography coupled with mass spectrometry (LC/MS) has been increasingly used for screening purposes in forensic toxicology. These techniques have the advantages of low time/resource-consuming and high versatility and have been applied in numerous new multi-analytes methods. The new psychoactive substance (NPS) phenomenon provided a great impulse to this wide-range approach, but it is also important to keep the attention on “classical” psychoactive substances, such as benzodiazepines (BDZ). In this paper, a fully validated screening method in blood for the simultaneous detection of 163 substances (120 NPS and 43 other drugs) by a dynamic multiple reaction monitoring analysis through LC-MS/MS is described. The method consists of a deproteinization of 200 µL of blood with acetonitrile. The LC separation is achieved with a 100 mm long C18 column in 35 min. The method was very sensitive, with limits of quantification from 0.02 to 1.5 ng/mL. Matrix effects did not negatively affect the analytical sensitivity. This method proved to be reliable and was successfully applied to our routinary analytical activity in several forensic caseworks, allowing the identification and quantification of many BDZs and 3,4-methylenedioxypyrovalerone (MDPV).

Blood concentrations of new synthetic opioids

PURPOSE

Over the last decade, there has been a significant growth in the market and number of new psychoactive substances (NPS). One of the NPS groups that has grown rapidly in recent years, bringing a new set of problems, consists of new synthetic opioids. The extreme potency of these compounds poses a high risk of acute poisoning, as an overdose can cause respiratory depression. Most of the information regarding human pharmacokinetics of new opioids is based on toxicological case reports and the data on concentrations of new opioids in human blood are scarce. The interpretation of results usually requires a comparison to previously published cases; therefore, a referenced compilation of previously published concentration data would be useful.

METHODS

The data were collected by searching the PubMed and Scopus databases and by using the Google search engine. All the available data from articles and reports that measured new opioid concentrations in plasma, serum, or whole blood were included in the data analysis.

RESULTS

The presented tables list the observed concentrations in fatal and nonfatal cases involving 37 novel synthetic opioids.

CONCLUSIONS

Blood levels of new opioids are extremely difficult to interpret. Low blood concentrations of these substances do not rule out acute poisoning as their high potency creates a risk of respiratory depression even at low doses. Opioid tolerance, frequent presence of other drugs, and additional diseases make it impossible to define concentration ranges, especially the minimum fatal concentrations. This report provides quick access to the source articles quantifying novel synthetic opioids.

Sensitive Screening of New Psychoactive Substances in Serum Using Liquid-Chromatography Quadrupole Time-of-Flight Mass Spectrometry

Analysis of new psychoactive substances (NPS) still pose a challenge for many institutions due to the number of available substances and the constantly changing drug market. Both new and well-known substances keep appearing and disappearing on the market, making it hard to adapt analytical methods in a timely manner. In this study we developed a qualitative screening approach for serum samples by means of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Samples were measured in data-dependent auto-MS/MS mode and identified by fragment spectra comparison, retention time and accurate mass. Approximately 500 NPS, including 195 synthetic cannabinoids, 180 stimulants, 86 hallucinogens, 26 benzodiazepines and 7 others were investigated. Serum samples were fortified to 1 ng/mL and 10 ng/mL concentrations to estimate approximate limits of identification. Samples were extracted using solid-phase extraction with non-endcapped C18 material and elution in two consecutive steps. Benzodiazepines were eluted in the first step, while substances of other NPS subclasses were distributed among both extracts. To determine limits of identification, both extracts were combined. 96 % (470/492) of investigated NPS were detected in 10 ng/mL samples and 88 % (432/492) were detected in 1 ng/mL samples. Stimulants stood out with higher limits of identification, possibly due to instability of certain methcathinone derivatives. However, considering relevant blood concentrations, the method provided sufficient sensitivity for stimulants as well as other NPS subclasses. Data-dependent acquisition was proven to provide high sensitivity and reliability when combined with an information-dependent preferred list, without losing its untargeted operation principle. Summarizing, the developed method fulfilled its purpose as a sensitive untargeted screening for serum samples and allows uncomplicated expansion of the spectral library to include thousands of targets.