Fatalities, Cerebral Hemorrhage, and Severe Cardiovascular Toxicity After Exposure to the New Psychoactive Substance 4-Fluoroamphetamine: A Prospective Cohort Study

Drug Use during Incarceration: A Comprehensive Quality and Prevalence Study in Three Danish Prisons

BACKGROUND

Drug use in Danish prisons has previously not been investigated in detail using confirmatory, laboratory analysis. The objective of the present quality study, initiated by the Danish Prison and Probation Service, was to i) evaluate the performance of an initial, on-site drug screening strategy; ii) gain insights into emerging drug trends; and iii) suggest evidence-based strategies for future drug testing.

METHODS

Over a two-year period, routine urine samples (n = 1952 from 710 inmates) from three Danish prisons were subjected to comprehensive drug testing. Immunoassay screening was conducted on-site. A parallel sample aliquot was forwarded to laboratory analysis by confirmatory methods: High-performance liquid chromatography and tandem mass spectrometry (LC-MS/MS) and gas chromatography and mass spectrometry (GC-MS) targeting 56 drugs-of-abuse/medical drugs, 26 key metabolites, 41 new psychoactive substances (NPS), including specific biomarkers for heroin, crack cocaine, or ethanol (a total of 123 target analytes/sample).

RESULTS

The on-site immunoassay method showed a sensitivity from 66 to 100%; specificity was above 98%; accuracy was above 95%. Laboratory analysis detected compounds not screened for including tramadol, oxycodone, buprenorphine, ketamine, MDMA, 4-fluoroamphetamine, and GHB. The prevalence of drug use was in the order: cannabis > ethanol > cocaine > benzodiazepines > amphetamine.

CONCLUSION

The performance of the immunoassay was found acceptable; however, the screening program was inadequate for detecting other significant substances. Based on these findings, a broader screening method will be implemented in future at Danish Prisons to minimize false negative results. The data did not indicate a trend of using NPS in Danish prisons.

The association of amfetamines and cathinones with acute coronary syndrome - a systematic review

BACKGROUND

It is well known that cocaine increases the risk of acute coronary syndrome. However, it is uncertain if the use of other stimulants, such as amfetamines and cathinones, is also related to acute coronary syndrome.

OBJECTIVES

To identify all reported cases of acute coronary syndrome related to the use of amfetamines and cathinones, the type of acute coronary syndrome, the atherothrombotic aetiology, and the mortality rate.

METHODS

A systematic literature search in PubMed, Embase database, Cochrane library, PsycInfo and Web of Science was performed from inception until 31 August 2022. All original articles in English or Dutch describing adult patients with acute coronary syndrome after the use of amfetamines or cathinones were included. The main outcome was the occurrence of acute coronary syndrome associated with amfetamine-type stimulants or cathinones. Data were collected and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

A total of 11,605 articles were identified, 56 of which met the inclusion criteria. A total of 160 patients presented with acute coronary syndrome after five different types of amfetamines, namely, amfetamine (n = 48), metamfetamine (n = 98), 3,4-methylenedioxymetamfetamine (n = 11), fenethylline (n = 2), and 4-fluoroamfetamine (n = 1). Khat chewing was associated with acute coronary syndrome (n = 4234), as were three different types of synthetic cathinones, namely, non-defined cathinones (n = 1), 4-methylmethcathinone (n = 1), and α-pyrrolidinopentiophenone (n = 1). In patients with a known acute coronary syndrome type (n = 157), ST-segment elevation myocardial infarction was diagnosed in 53 patients (75%) and non-ST-segment elevation myocardial infarction in 18 patients (25%). Of the ST-segment elevation myocardial infarction patients, 36% were diagnosed with significant coronary stenosis or thrombus. The mortality rate for khat-associated acute coronary syndrome, with more often male and older patients with fewer cardiovascular risk factors, was higher compared to non-khat-associated acute coronary syndrome. For amfetamine, metamfetamine, and 3,4-methylenedioxymetamfetamine, mortality associated with ST--segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction was 14% and 7%, respectively. Risk factors for acute coronary syndrome were infrequently reported, and risk stratification scores were not reported.

CONCLUSION

There is evidence that amfetamine-type stimulants and cathinones are associated with the occurrence of acute coronary syndrome. Khat chewing appears to be a risk factor for acute coronary syndrome. Amfetamine, metamfetamine, 3,4-methylenedioxymetamfetamine, fenethylline, 4-fluoroamfetamine, and synthetic cathinones were also reported in relation to acute coronary syndrome. However, this evidence is limited, of low quality and with a low number of reported cases. Further prospective studies need to be conducted.

Fatal Intoxications from a Combination of 4-Fluoroamphetamine and 25C-NBOMe

Six fatalities have occurred from the ingestion of a combination of new psychoactive substances (NPSs), 4-fluoroamphetamine (4FA) and 2-(4-chloro-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25C-NBOMe) over a 9-month period. Four of these fatalities (one older female and three young males) were from direct adverse effects of drugs, and one each from a fall while being intoxicated and during restraint. All cases were subject to full postmortem examinations that included collection of femoral blood. The four drug-caused fatalities had postmortem blood concentrations for 4FA and 25C-NBOMe of 330-682 ng/L (median 417) and 1.4-12 ng/mL (median 4.3), respectively. The other two cases (both young males) where death was considered to have been caused indirectly by drug intoxication had 4FA and 25C-NBOMe postmortem concentrations of 21 and 123 ng/mL, and 1.8 and 4.5 ng/mL, respectively. None of these cases showed concentrations of drugs that suggested use of high recreational doses. In one drug-caused death, capsules and a brown powder obtained from the scene were found to contain a mixture of these two NPSs. With the exception of one drug-caused death, other drugs were detected; however, the effects of the two NPSs together were regarded as the primary triggers for the deaths. There were no consistent symptoms or pathology in these cases; however, agitation/aggression was observed in two cases prior to their collapse, with seizures in possibly three cases. Pulmonary and/or cerebral edema was noted in three cases. Potentially significant natural disease (a mildly enlarged heart) was only observed in one drug-caused case. These cases illustrate a possible increased risk of sudden death with this combination of drugs, both of which can elevate serotonin concentrations as well as act as strong stimulants. These cases also illustrate the difficulty in detecting NPS in cases where no prior information is available that might suggest their use.

New Psychoactive Substances Intoxications and Fatalities during the COVID-19 Epidemic

In January 2020, the World Health Organization (WHO) issued a Public Health Emergency of International Concern, declaring the COVID-19 outbreak a pandemic in March 2020. Stringent measures decreased consumption of some drugs, moving the illicit market to alternative substances, such as New Psychoactive Substances (NPS). A systematic literature search was performed, using scientific databases such as PubMed, Scopus, Web of Science and institutional and government websites, to identify reported intoxications and fatalities from NPS during the COVID-19 pandemic. The search terms were: COVID-19, SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, coronavirus disease 2019, intox*, fatal*, new psychoactive substance, novel psychoactive substance, smart drugs, new psychoactive substance, novel synthetic opioid, synthetic opioid, synthetic cathinone, bath salts, legal highs, nitazene, bath salt, legal high, synthetic cannabinoid, phenethylamine, phencyclidine, piperazine, novel benzodiazepine, benzodiazepine analogue, designer benzodiazepines, tryptamine and psychostimulant. From January 2020 to March 2022, 215 NPS exposures were reported in Europe, UK, Japan and USA. Single NPS class intoxications accounted for 25, while mixed NPS class intoxications represented only 3 cases. A total of 130 NPS single class fatalities and 56 fatalities involving mixed NPS classes were published during the pandemic. Synthetic opioids were the NPS class most abused, followed by synthetic cathinones and synthetic cannabinoids. Notably, designer benzodiazepines were frequently found in combination with fentalogues. Considering the stress to communities and healthcare systems generated by the pandemic, NPS-related information may be underestimated. However, we could not define the exact impacts of COVID-19 on processing of toxicological data, autopsy and death investigations.

Clinical characteristics of new psychoactive substances: A multicenter study

BACKGROUND

New psychoactive substances (NPS) are synthetic alternatives to illicit drug abuse that are not under international control but may pose a public health threat. Moreover, the symptoms and signs of NPS users may be quite variable. This study aimed to figure out the clinical characteristics of NPS users presented to the emergency department (ED).

METHODS

A total of 1385 cases were tested via urine toxicity screening from March 25, 2019, to January 28, 2020, in six medical centers, and ten hospitals, in Taiwan. A total of 123 non-NPS cases and 77 NPS-use cases were enrolled in this study. We compared the patient data-vital signs, presentation, co-morbidities, behaviors, symptoms, electrocardiograms, laboratory data, length of stays-and outcomes of NPS users and non-NPS drug users.

RESULTS

NPS users were 5.7 years younger than the non-NPS drug users (37 vs. 42.7 years, p = 0.022). Presently, NPS users had a 2.6-fold (27.2%) higher rate of suicide and a 2.9-fold (11.7%) greater possibility of violence than non-NPS drug users. Moreover, in NPS users, eye-opening was affected at a scale of 3.1 versus 3.4 (p = 0.048) in non-NPS drug users in the evaluation of consciousness and they experienced a 4.3-fold greater feeling of palpitation (p = 0.024) and had 8.1-fold higher chance of presenting facial flush (p = 0.032) than non-NPS drug users.

CONCLUSION

NPS users are relatively younger, are more likely to experience facial flush and palpitation and engage in more self-harm, violence, and suicide than non-NPS drug users. Physicians need to pay attention to people who have altered, bizarre mental statuses with the clinical characteristics described above.

4-Fluoroamphetamine (4-FA) intoxication results in exaggerated blood pressure effects compared to MDMA and amphetamine: A retrospective analysis

Objective

4-Fluoroamphetamine (4-FA) is an amphetamine-type stimulant, with effects comparable to amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Severe 4-FA-related complications, such as cardiomyopathy, myocardial infarction, and cerebral hemorrhage, have been described. The aim of this study was to explore the cardiovascular symptoms and complications in 4-FA and compare them to MDMA and amphetamine in intoxicated patients who presented to the emergency department (ED).

Methods

Between November 2015 and March 2020, all self-reported 4-FA, MDMA, and amphetamine-intoxicated adult patients that presented at the ED of an inner-city hospital in Amsterdam, were retrospectively analyzed for cardiovascular symptoms, vital parameters, cardiovascular complications, interventions, admission rate, and Poisoning Severity Score (PSS).

Results

A total of 582 patients were included, of which 31 (5.3%) with 4-FA intoxication (10/31 mono-intoxications, 32.3%), 406 (69.8%) with MDMA (59/406 mono-intoxications, 14.5%), 100 (17.2%) with amphetamine (10/100 mono-intoxications, 10.0%), and 45 (7.7%) with a cross intoxication of these drugs. 4-FA mono-intoxicated patients experienced more headache (n = 8; 80.0%) compared to MDMA (n = 2; 3.3%; P < 0.001) and amphetamine mono-intoxicated patients (n = 0; 0.0%; P < 0.001) and their systolic blood pressure was higher (164 mm Hg ± 31 vs 139 mm Hg ± 19; P = 0.031 vs 135 mm Hg ± 22; P = 0.033, respectively). Severe 4-FA-related cardiovascular complications included Takotsubo cardiomyopathy (n = 1; 3.2%), subarachnoid hemorrhage (n = 1; 3.2%), and hypertensive urgency (n = 2; 6.5%).

Conclusions

4-FA intoxication-related ED symptoms resemble MDMA and amphetamine complications, although patients presented more often with headache and hypertension. Severe 4-FA-related cardiovascular complications occurred in 40% of mono-intoxications.

3-Methylmethcathinone (3-MMC) Poisonings: Acute Clinical Toxicity and Time Trend Between 2013 and 2021 in the Netherlands

STUDY OBJECTIVE

The synthetic cathinone 3-methylmethcathinone (3-MMC, or metaphedrone) has recently gained popularity. We studied the numbers of 3-MMC poisonings over time and the clinical effects following poisonings with 3-MMC.

METHODS

We performed a retrospective study on the numbers of self-reported 3-MMC poisonings to the Dutch Poisons Information Center (DPIC) from 2013 to June 2021. For poisonings reporting 3-MMC only, the symptoms were extracted and the Poisoning Severity Score (PSS) was determined. From 2016 to June 2019, a prospective cohort study on poisonings reporting only 3-MMC was performed, in which details on the clinical courses were collected through telephone interviews.

RESULTS

From 2013 to June 2021, the DPIC was consulted on 184 3-MMC poisonings. The number of poisonings increased from 1 in 2013 to 70 in the first half of 2021. In 84 poisonings with only 3-MMC (46%), sympathomimetic symptoms were commonly reported, including tachycardia (n=29, 35%), hypertension (n=17, 20%), and agitation (n=16, 19%). The initial PSS was usually minor (n=37, 44%) to moderate (n=39, 46%). Five patients (6%) experienced severe effects, including 3 patients experienced severe hypertension (systolic blood pressure >180 mmHg; n=3) and nonfatal cardiac arrest (n=1). Sympathomimetic symptoms (n=8) were also reported in the prospective cohort study. The percentage of moderate poisonings increased (n=6, 75%), and 1 (13%) severe poisoning was observed. Analytical confirmation of 3-MMC exposure was performed in 2 cases.

CONCLUSION

The number of 3-MMC poisonings reported to the DPIC has increased over time. Most poisonings with 3-MMC resulted in moderate toxicity and involved sympathomimetic effects, while severe effects were observed in 5 cases.

Significant toxicity following an increase in poisonings with designer benzodiazepines in the Netherlands between 2010 and 2020

BACKGROUND

Designer benzodiazepines (DBs) are an emerging class of new psychoactive substances. While structurally derived from pharmaceutical benzodiazepines, their toxicological profile is less clear. We investigated time trends in the rate of DB poisonings and their clinical toxicity.

METHODS

A retrospective observational study was performed on the incidence rate of DB poisonings, relative to all recreational drug poisonings reported to the Dutch Poisons Information Center (DPIC) from 2010 to 2020. Time-trend analysis was performed using Poisson regression. A prospective cohort study was performed on toxicity of DBs, including the Poisoning Severity Score, from January 2016-June 2019. Data was collected through telephone interviews.

RESULTS

Between 2010 and 2020, the DPIC was consulted on 142 DB exposures. The incidence rate of DB exposures increased from 0.1% to 4.3%, with a year effect estimate of 1.35 (95% CI [1.14;1.54]). Twenty different DBs were reported, mostly etizolam (33%), clonazolam (17%), and flunitrazolam (8%). During consultation (often shortly after exposure), poisoning was graded moderate-severe in 29% of cases (n = 146). In the prospective cohort sample with follow-up (n = 22), 86% of cases (n = 19) showed a moderate-severe poisoning. The severity of poisoning did not differ between mono- and mixed intoxications. Frequently reported symptoms in the prospective cohort sample included drowsiness (86%), confusion (59%), and agitation (55%). Coma was observed in seven cases (32%) and respiratory depression requiring mechanical ventilation in five cases (23%).

CONCLUSION

The rate of DB poisonings reported to the DPIC strongly increased from 2010 to 2020, indicating increased (ab)use of DBs. Most DB exposures resulted in moderate-severe toxicity with neurological effects.

4-Fluoromethamphetamine (4-FMA) induces in vitro hepatotoxicity mediated by CYP2E1, CYP2D6, and CYP3A4 metabolism

4-Fluoromethamphetamine (4-FMA) is an amphetamine-like psychoactive substance with recognized entactogenic and stimulant effects, but hitherto unclear toxicological mechanisms. Taking into consideration that the vast majority of 4-FMA users consume this substance through oral route, the liver is expected to be highly exposed. The aim of this work was to determine the hepatotoxic potential of 4-FMA using in vitro hepatocellular models: primary rat hepatocytes (PRH), human hepatoma cell lines HepaRG and HepG2, and resorting to concentrations ranging from 37 μM to 30 mM, during a 24-h exposure. EC₅₀ values, estimated from the MTT viability assay data, were 2.21 mM, 5.59 mM and 9.57 mM, for each model, respectively. The most sensitive model, PRH, was then co-exposed to 4-FMA and cytochrome P450 (CYP) inhibitors to investigate the influence of metabolism on the toxicity of 4-FMA. Results show that CYP2E1, CYP3A4 and CYP2D6 have major roles in 4-FMA cytotoxicity. Inhibition of CYP2D6 and CYP3A4 led to left-geared shifts in the concentration-response curves of 4-FMA, hinting at a role of these metabolic enzymes for detoxifying 4-FMA, while CYP2E1 inhibition pointed towards a toxifying role of this enzyme in 4-FMA metabolism at physiologically-relevant concentrations. The drug also destabilised mitochondrial membrane potential and decreased ATP levels, increased the production of reactive oxygen and nitrogen species and compromised thiol antioxidant defences. 4-FMA further affected PRH integrity by interfering with the machinery of apoptosis and necrosis, increasing the activity of initiator and effector caspases, and causing loss of cell membrane integrity. Potential for autophagy was also observed. This research contributes to the growing body of evidence regarding the toxicity of new psychoactive substances, in particular regarding their hepatotoxic effects; the apparent influence of metabolism over the resulting cytotoxicity of 4-FMA shows that there is a substantial degree of unpredictability of the consequences for users that could be independent of the dose.

Molecular and clinical aspects of potential neurotoxicity induced by new psychoactive stimulants and psychedelics

New psychoactive stimulants and psychedelics continue to play an important role on the illicit new psychoactive substance (NPS) market. Designer stimulants and psychedelics both affect monoaminergic systems, although by different mechanisms. Stimulant NPS primarily interact with monoamine transporters, either as inhibitors or as substrates. Psychedelic NPS most potently interact with serotonergic receptors and mediate their mind-altering effects mainly through agonism at serotonin 5-hydroxytryptamine-2A (5-HT_2A) receptors. Rarely, designer stimulants and psychedelics are associated with potentially severe adverse effects. However, due to the high number of emerging NPS, it is not possible to investigate the toxicity of each individual substance in detail. The brain is an organ particularly sensitive to substance-induced toxicity due to its high metabolic activity. In fact, stimulant and psychedelic NPS have been linked to neurological and cognitive impairments. Furthermore, studies using in vitro cell models or rodents indicate a variety of mechanisms that could potentially lead to neurotoxic damage in NPS users. Cytotoxicity, mitochondrial dysfunction, and oxidative stress may potentially contribute to neurotoxicity of stimulant NPS in addition to altered neurochemistry. Serotonin 5-HT_2A receptor-mediated toxicity, oxidative stress, and activation of mitochondrial apoptosis pathways could contribute to neurotoxicity of some psychedelic NPS. However, it remains unclear how well the current preclinical data of NPS-induced neurotoxicity translate to humans.

Novel Phenethylamines and Their Potential Interactions With Prescription Drugs: A Systematic Critical Review

BACKGROUND

The novel phenethylamines 4-fluoroamphetamine (4-FA) and 2,5-dimethoxy-4-bromophenethylamine (2C-B) fall in the top 10 most used new psychoactive substances (NPSs) among high-risk substance users. Various phenethylamines and NPS are also highly used in populations with mental disorders, depression, or attention deficit hyperactivity disorder (ADHD). Moreover, NPS use is highly prevalent among men and women with risky sexual behavior. Considering these specific populations and their frequent concurrent use of drugs, such as antidepressants, ADHD medication, and antiretrovirals, reports on potential interactions between these drugs, and phenethylamines 4-FA and 2C-B, were reviewed.

METHODS

The authors performed a systematic literature review on 4-FA and 2C-B interactions with antidepressants (citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, duloxetine, bupropion, venlafaxine, phenelzine, moclobemide, and tranylcypromine), ADHD medications (atomoxetine, dexamphetamine, methylphenidate, and modafinil), and antiretrovirals.

RESULTS

Limited literature exists on the pharmacokinetics and drug-drug interactions of 2C-B and 4-FA. Only one case report indicated a possible interaction between 4-FA and ADHD medication. Although pharmacokinetic interactions between 4-FA and prescription drugs remain speculative, their pharmacodynamic points toward interactions between 4-FA and ADHD medication and antidepressants. The pharmacokinetic and pharmacodynamic profile of 2C-B also points toward such interactions, between 2C-B and prescription drugs such as antidepressants and ADHD medication.

CONCLUSIONS

A drug-drug (phenethylamine-prescription drug) interaction potential is anticipated, mainly involving monoamine oxidases for 2C-B and 4-FA, with monoamine transporters being more specific to 4-FA.

Acute onset heart failure due to reverse type Takotsubo cardiomyopathy caused by a single dose of 4-Fluoroamphetamine in a healthy young individual

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4-Fluoroamphetamine (4-FA) is a popular new psychoactive stimulant that is used for recreational purposes.

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A single dose of 4-FA can lead to reverse type Takotsubo cardiomyopathy with cardiogenic shock.

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4-FA use can cause a very sudden onset of severe symptoms.

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Due to mild and late onset of effect, 4-FA users have the tendency to take an extra dose.

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Phosphodiesterase-3-inhibitors are effective for amphetamine type stimulant induced Takotsubo cardiomyopathy.

Introduction

4-fluoroamphetamine (4-FA) is a novel psychoactive stimulant with a global presence on the drug market. Despite the popularity of 4-FA, data on severe adverse effects are scarce. We present a case of laboratory confirmed 4-FA mono intoxication causing acute heart failure due to a reverse type Takotsubo cardiomyopathy.

Case

A 20-year-old male with no previous medical history and no reported previous drug use, presented to the emergency department (ED) with complaints of headache, nausea and vomiting, approximately 4.5 h after the ingestion of a single 4-FA pill. After 30 min his condition deteriorated with severe hypertension, tachycardia and respiratory failure. Echocardiography showed a reverse type Takotsubo cardiomyopathy. The patient was successfully treated with mechanical ventilation, a phosphodiesterase-3-inhibitor (PDE3-inhibitor) and diuretics. Three months after hospital admission, the patient was free of complaints and his left ventricular function fully recovered.

Conclusion

Recreational use of 4-FA may result in acute onset life-threatening cardiorespiratory toxicity, preceded by severe hypertension, even in drug-naïve patients without any medical history. Emergency physicians and cardiologists should be cautious not to underestimate life-threatening 4-FA complications.

Chiral Serum Pharmacokinetics of 4-Fluoroamphetamine after Controlled Oral Administration: Can (R)/(S) Concentration Ratios Help in Interpreting Forensic Cases?

Over the last two decades, misuse of 4-fluoroamphetamine (4-FA) became an emerging issue in many European countries. Stimulating effects last for 4-6 hours and can impact psychomotor performance. The metabolism of amphetamine-type stimulants is stereoselective and quantification of (R)- and (S)-enantiomers has been suggested for assessing time of use. To date no data on enantioselective pharmacokinetics is available for 4-FA in serum samples. An enantioselective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed using a chiral Phenomenex® Lux 3 μm AMP column. Validation of the method showed satisfactory selectivity, sensitivity, linearity (0.5-250 ng/mL), precision and accuracy. Recreational stimulant users orally ingested two doses (100 mg, n=12, and 150 mg, n=5) of 4-FA. Blood samples were drawn prior to application and over a period of 12 hours after ingestion and analyzed for 4-FA enantiomers. Peak concentrations and corresponding times did not differ significantly between the enantiomers (mean (R)/(S)-ratio at tmax 1.05, 0.85-1.16). With mean 12.9 (8.3-16.1) hours, apparent elimination half-lives (t1/2) were significantly (p < 0.01) longer for (R)-4-FA than for (S)-4-FA (6.0 hours; range 4.4-10.2 hours) and independent of the dose given. Over time, (R)/(S)-concentration-ratios were linearly increasing in all subjects to maximum ratios of 2.00 (1.08-2.77) in the last samples (after 12 hours). The slopes of the (R)/(S)-ratio exhibited marked inter-individual differences (0.023 to 0.157 h-1, mean 0.095 h-1). Ratios higher than 1.60 only appeared earliest after a minimum of 6 hours and therefore suggest the absence of acute drug effects. Different elimination half-lives of enantiomers lead to constantly increasing (R)/(S)-concentration-ratios. Consequently, ratios of 4-FA enantiomers in serum are a promising indicator for assessment of the time of drug consumption.

The Clinical Toxicology of 4-Bromo-2,5-dimethoxyphenethylamine (2C-B): The Severity of Poisoning After Exposure to Low to Moderate and High Doses

STUDY OBJECTIVE

We studied the severity of poisoning after exposure to low to moderate and high doses of 4-bromo-2,5-dimethoxyphenethylamine (2C-B).

METHODS

Patients for whom the Dutch Poisons Information Centre was consulted for 2C-B exposure from 2016 to 2018 were included in a prospective cohort study. Data were collected through telephone interviews with the physician or patient. Patients were categorized according to the reported 2C-B dose: low to moderate (up to 20 mg), high (greater than 20 mg), or unknown. Presence of 2C-B was analyzed in leftover drug and biological samples with liquid/gas chromatography-mass spectrometry. The severity of poisoning was graded with the Poisoning Severity Score.

RESULTS

We included 59 patients, of whom 32 could be followed up. Low to moderate 2C-B doses were reported by 9 patients (28%), high doses by 17 (53%), and unknown doses by 6 (19%). Poisoning was moderate in the majority of patients in both the low- to moderate-dose and high-dose groups. Frequently reported symptoms included mydriasis, agitation or aggression, hallucinations, confusion, anxiety, hypertension, and tachycardia. The presence of 2C-B was confirmed in 5 patients in urine (n=3) or drug samples (n=4).

CONCLUSION

In this study, most 2C-B poisonings resulted in moderate toxicity even at high reported doses up to 192 mg. No severe cases were observed. The clinical course was usually short-lived (up to 24 hours) and typically involved hallucinations in addition to mild somatic effects.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABAA) or GABAB receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-D-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB1) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.

Cardiotoxicity screening of illicit drugs and new psychoactive substances (NPS) in human iPSC-derived cardiomyocytes using microelectrode array (MEA) recordings

The use of recreational drugs, including new psychoactive substances (NPS), is paralleled by emergency department visits of drug users with severe cardiotoxicity. Drug-induced cardiotoxicity can be the (secondary) result of increased norepinephrine blood concentrations, but data on potential drug-induced direct effects on cardiomyocyte function are scarce. The presence of hundreds of NPS therefore calls for efficient screening models to assess direct cardiotoxicity. We investigated effects of four reference compounds (3-30 nM dofetilide, nifedipine and isoproterenol, and 1-10 μM mexiletine) and six recreational drugs (0.01-100 μM cocaine, 0.01-1000 μM amphetamine, MDMA, 4-fluoroamphetamine, α-PVP and MDPV) on cardiomyocyte function (beat rate, spike amplitude and field potential duration (FPD ≈ QT interval in ECGs)), using Pluricyte® human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes cultured on ready-to-use CardioPlate™ multi-well microelectrode arrays (mwMEAs). Moreover, the effects of exposure to recreational drugs on cell viability were assessed. Effects of reference compounds were in accordance with the literature, indicating the presence of hERG potassium (dofetilide), sodium (mexiletine) and calcium (nifedipine) channels and α-adrenergic receptors (isoproterenol). All recreational drugs decreased the spike amplitude at 10-100 μM. All amphetamine-type stimulants and α-PVP decreased the beat rate at 300 μM, while cocaine and MDPV did so at 10 μM and 30 μM, respectively. All drugs increased the FPD, however at varying concentrations. MDMA, MDPV and amphetamine affected cardiomyocyte function at concentrations relevant for human exposure, while other drugs affected cardiomyocyte function only at higher concentrations (≥ 10 μM). Cell viability was only mildly affected at concentrations well above the lowest concentrations affecting cardiomyocyte function. We demonstrate that MEA recordings of hiPSC-derived cardiomyocytes enable screening for acute, direct effects on cardiomyocyte function. Our data further indicate that tachycardia in patients exposed to recreational drugs is likely due to indirect drug effects, while prolonged repolarization periods (prolonged QT_c interval) could (partly) result from direct drug effects on cardiomyocyte function.

Para-Halogenation Affects Monoamine Transporter Inhibition Properties and Hepatocellular Toxicity of Amphetamines and Methcathinones

Halogenated derivatives of amphetamine-type stimulants are appearing on the drug market, often with altered pharmacological profile and sometimes different legal status compared to the non-halogenated substances. The aim of the present study was to investigate the pharmacological profile and hepatocellular toxicity of para-halogenated amphetamines and cathinones. The potential of amphetamine, 4-fluoroamphetamine, 4-chloroamphetamine, methcathinone, 4-fluoromethcathinone, and 4-chloromethcathinone to inhibit the monoamine transporters for norepinephrine, dopamine, and serotonin was determined in transporter-transfected human embryonic kidney 293 cells. Cell membrane integrity, ATP content, oxygen consumption rate, and superoxide levels were measured in human hepatoma HepG2 cells after exposure to the substances for 24 h. All compounds inhibited the norepinephrine transporter at submicromolar concentrations and the dopamine transporter at low micromolar concentrations. The selectivity of the compounds to inhibit the dopamine versus serotonin transporter decreased with increasing size of the para-substituent, resulting in potent serotonin uptake inhibition for the halogenated derivatives. All substances depleted the cellular ATP content at lower concentrations (0.25–2 mM) than cell membrane integrity loss occurred (≥0.5 mM), suggesting mitochondrial toxicity. The amphetamines and 4-chloromethcathinone additionally impaired the mitochondrial respiratory chain, confirming mitochondrial toxicity. The following toxicity rank order for the para-substituents was observed: chloride > fluoride > hydrogen. In conclusion, para-halogenation of stimulants increases the risk for serotonergic neurotoxicity. Furthermore, para-halogenation may increase hepatic toxicity mediated by mitochondrial impairment in susceptible users.

Pharmacology of MDMA- and Amphetamine-Like New Psychoactive Substances

New psychoactive substances (NPS) with amphetamine-, aminoindan-, and benzofuran basic chemical structures have recently emerged for recreational drug use. Detailed information about their psychotropic effects and health risks is often limited. At the same time, it emerged that the pharmacological profiles of these NPS resemble those of amphetamine or 3,4-methylenedioxymethamphetamine (MDMA). Amphetamine-like NPS induce psychostimulation and euphoria mediated predominantly by norepinephrine (NE) and dopamine (DA) transporter (NET and DAT) inhibition and transporter-mediated release of NE and DA, thus showing a more catecholamine-selective profile. MDMA-like NPS frequently induce well-being, empathy, and prosocial effects and have only moderate psychostimulant properties. These MDMA-like substances primarily act by inhibiting the serotonin (5-HT) transporter (SERT) and NET, also inducing 5-HT and NE release. Monoamine receptor interactions vary considerably among amphetamine- and MDMA-like NPS. Clinically, amphetamine- and MDMA-like NPS can induce sympathomimetic toxicity. The aim of this chapter is to review the state of knowledge regarding these substances with a focus on the description of the in vitro pharmacology of selected amphetamine- and MDMA-like NPS. In addition, it is aimed to provide links between pharmacological profiles and in vivo effects and toxicity, which leads to the conclusion that abuse liability for amphetamine-like NPS may be higher than for MDMA-like NPS, but that the risk for developing the life-threatening serotonin syndrome may be increased for MDMA-like NPS.