Role of voltage-gated sodium, potassium and calcium channels in the development of cocaine-associated cardiac arrhythmias

Ischemic and non-ischemic myocardial injuries at autopsy- an overview for forensic pathologists

Cardiovascular diseases are major causes of morbidity and death worldwide, and most cardiac deaths are related to ischemic injury of the myocardium (myocardial infarction). As underlined in the current clinical definition and classification of myocardial infarctions, not all myocardial injuries are due to ischemia: irreversible injury, ending in necrosis, can be induced also by various other factors, such as infections, immune disorders, physical and chemical agents, and trauma. This is supported by clinical studies showing that elevated serum levels of cardiac troponins, as a measure of myocardial damage, are also a common finding in the non-ischemic types of myocardial injury. Forensic pathologists confronted with autopsy findings suggestive of myocardial injury should therefore realize that both ischemic and non-ischemic forms of myocardial death can be observed, and not only in natural but also non-natural deaths (intoxications, asphyxia, traumatic and iatrogenic deaths, and others). Distinguishing these different types of injuries and underlying diseases or circumstances of death is critical, not only to determine the cause and mechanism of death, but also to help investigate often challenging medico-legal scenarios. This article reviews the broad spectrum of ischemic and non-ischemic myocardial injuries in natural and violent deaths. From this perspective we propose a diagnostic approach to myocardial injuries in a forensic pathology context.

The Impact of Potent Addictive Substances on Angiogenic Behavior: A Comprehensive Review

Angiogenesis, the formation of new vasculature from preexisting vasculature, is involved in the development of several diseases as well as various physiological processes. Strict cooperation of proangiogenic and antiangiogenic factors mediates the control of angiogenesis. The fundamental steps in angiogenesis include endothelial cell proliferation, migration, and invasion. Addictive substances, which are considered therapeutic candidates in research and medicine, are classified as natural substances, such as nicotine, or synthetic substances, such as synthetic cannabinoids. Addictive substances have been shown to either enhance or suppress angiogenesis. This review article provides an overview of recent studies concerning the effects of several addictive substances on the process of angiogenesis. Google Scholar and PubMed were used to collect the scientific literature used in this review. The addictive substances addressed in this review are nicotine, opioids such as morphine and heroin, alcohol, cocaine, methamphetamine, and cannabinoids. An accurate assessment of the influence of these substances on the angiogenic process may help to construct a potentially effective therapeutic protocol to control and treat several angiogenesis-related diseases.

Brugada Phenotype Following a Cocaine Overdose

Brugada syndrome is a rare cardiac condition characterized by distinctive electrocardiogram patterns, predisposing individuals to fatal arrhythmias. While primarily linked to a loss-of-function mutation in the SCN5A gene, acquired forms of the syndrome have been associated with various factors, including drug use. We present a case of a 31-year-old female who presented to the emergency department unresponsive following cocaine use and developed type 1 Brugada ECG patterns alongside an incomplete right bundle branch block in V1-V3, ST elevations with biphasic waves, and diffuse repolarization abnormalities with J point deviations while in the intensive care unit. This study aimed to discuss the complexity of managing drug-induced Brugada-like findings and highlights the need for further research into the mechanisms underlying cocaine-induced cardiac effects. We aimed to discuss potential mechanisms for the impact of cocaine as its role as a sodium channel blocker and its potential effects on connexin 43 in the context of Brugada syndrome. This study also reinforced the importance of differentiating between true Brugada syndrome and other similar ECG changes for appropriate care management.

Single cocaine exposure attenuates the intrinsic excitability of CRH neurons in the ventral BNST via Sigma-1 receptors

The ventral bed nucleus of the stria terminalis (vBNST) plays a key role in cocaine addiction, especially relapse. However, the direct effects of cocaine on corticotropin-releasing hormone (CRH) neurons in the vBNST remain unclear. Here, we identify that cocaine exposure can remarkably attenuate the intrinsic excitability of CRH neurons in the vBNST in vitro. Accumulating studies reveal the crucial role of Sigma-1 receptors (Sig-1Rs) in modulating cocaine addiction. However, to the authors' best knowledge no investigations have explored the role of Sig-1Rs in the vBNST, let alone CRH neurons. Given that cocaine acts as a type of Sig-1Rs agonist, and the dramatic role of Sig-1Rs played in intrinsic excitability of neurons as well as cocaine addiction, we employ BD1063 a canonical Sig-1Rs antagonist to block the effects of cocaine, and significantly recover the excitability of CRH neurons. Together, we suggest that cocaine exposure leads to the firing rate depression of CRH neurons in the vBNST via binding to Sig-1Rs.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

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.

MicroRNA-423-5p Mediates Cocaine-Induced Smooth Muscle Cell Contraction by Targeting Cacna2d2

Cocaine abuse increases the risk of atherosclerotic cardiovascular disease (CVD) and causes acute coronary syndromes (ACS) and hypertension (HTN). Significant research has explored the role of the sympathetic nervous system mediating the cocaine effects on the cardiovascular (CV) system. However, the response of the sympathetic nervous system alone is insufficient to completely account for the CV consequences seen in cocaine users. In this study, we examined the role of microRNAs (miRNAs) in mediating the effect of cocaine on the CV system. MiRNAs regulate many important biological processes and have been associated with both response to cocaine and CV disease development. Multiple miRNAs have altered expression in the CV system (CVS) upon cocaine exposure. To understand the molecular mechanisms underlying the cocaine response in the CV system, we studied the role of miRNA-423-5p and its target Cacna2d2 in the regulation of intracellular calcium concentration and SMC contractility, a critical factor in the modulation of blood pressure (BP). We used in vivo models to evaluate BP and aortic stiffness. In vitro, cocaine treatment decreased miR-423-5p expression and increased Cacna2d2 expression, which led to elevated intracellular calcium concentrations and increased SMC contractility. Overexpression of miR-423-5p, silencing of its target Cacna2d2, and treatment with a calcium channel blocker reversed the elevated SMC contractility caused by cocaine. In contrast, suppression of miR-423-5p increased the intracellular calcium concentration and SMC contractibility. In vivo, smooth muscle-specific overexpression of miR-423-5p ameliorated the increase in BP and aortic stiffness associated with cocaine use. Thus, miR-423-5p regulates SMC contraction by modulating Cacna2d2 expression increasing intracellular calcium concentrations. Modulation of the miR-423-5p-Cacna2d2-Calcium transport pathway may represent a novel therapeutic strategy to improve cocaine-induced HTN and aortic stiffness.

From Bumps to Binges: Overview of Deaths Associated with Cocaine in England, Wales and Northern Ireland (2000-2019)

The UK, as the "cocaine capital of Europe," currently accounts for ∼75% of all cocaine-related hospital admissions in Europe. This study aims to analyze the trends in cocaine-related deaths in England, Wales and Northern Ireland over 20 years (2000-2019). Cases reported to the National Programme on Substance Abuse Deaths (NPSAD) occurring between 2000 and 2019 where cocaine was detected at post-mortem (PM) were extracted for analysis. A total of 5,339 cases were retrieved, with an increase in the rate of reporting over time. Cocaine was deemed a cause of death and quantified in PM blood samples along with its major metabolite benzoylecgonine in 685 cases. Of these 685 cases, 25% (n = 170/685) occurred following acute use, 22% (n = 154/685) following chronic/binge use, 40% (n = 271/685) in combination with morphine, 4% (n = 29/685) in drug packer/swallower circumstances and 9% (n = 61/685) in a suicide context. Cardiac complications were evident in 22% of cases (n = 154/685). The average concentration of cocaine detected in cardiac cases (900 ng/mL) was considerably lower than that detected in cases where acute (19,100 ng/mL) or chronic/binge (6,200 ng/mL) dosing was evident. This is the first cocaine-related mortality study in these geographical areas. Deaths following cocaine use continue to rise despite its Class A drug listing in the UK. While underlying and external risk factors including polydrug use, cardiac complications and mental health can all contribute to the incidence of fatal drug toxicity following cocaine use, this study demonstrates that the risk of a cocaine overdose cannot be attributed to a specific blood concentration range.

Effect of Cocaine on Potassium-Evoked Release of Glutamate From Fetal Rat Brain Synaptosomes

Introduction Cocaine use during pregnancy can affect fetal brain development. A fetal brain injury could happen from the direct effect of cocaine on the developing brain or from the reduction of placental perfusion from vasoconstriction, which may lead to hypoxia-ischemia. A potential mechanism for brain injury could be due to a neurotransmitter imbalance within the brain, especially glutamate. In an immature rat brain synaptosome model, we explored the additive effect of cocaine alone on glutamate release and the effect of cocaine combined with simulated hypoxic depolarization using potassium as a surrogate. Method Rat pups' brains were dissected and placed on a chilled petri dish. They then entered the experimental protocol. The suspended synaptosomes were divided equally into four experimental groups (control, high potassium "surrogate to hypoxic stimulation," cocaine, and cocaine + high K). Reversed-phase high-performance liquid chromatography analyzed glutamate with fluorescent detection Results The glutamate level was lowest in the cocaine-only group, with a level of 1.96 × 104, compared to the control and high potassium group. However, combining cocaine with high potassium seemed to generate a synergistic effect, achieving the highest glutamate level of all groups with a value of 5.31 × 104. Post hoc Conover's test for multiple pairwise-comparison between groups was done. In comparing various solutions to control, we did not find a statistically significant difference with the cocaine-only solution with a p-value of 0.074. Also, on comparing various other solutions to each other, there was no statistically significant difference between cocaine vs. cocaine + high potassium a p-value of 0.074. Conclusion Our data support the conclusion that cocaine alone does not induce glutamate release from fetal rat brain synaptosomes. Exposure to high potassium does lead to glutamate release. However, cocaine greatly enhances glutamate release in the presence of high potassium levels. This could explain how cocaine affects brain maturation during pregnancy with a low oxygen tension environment in the placenta. This hypothesis should be tested in vivo.

Cocaine: An Updated Overview on Chemistry, Detection, Biokinetics, and Pharmacotoxicological Aspects including Abuse Pattern

Cocaine is one of the most consumed stimulants throughout the world, as official sources report. It is a naturally occurring sympathomimetic tropane alkaloid derived from the leaves of Erythroxylon coca, which has been used by South American locals for millennia. Cocaine can usually be found in two forms, cocaine hydrochloride, a white powder, or ‘crack’ cocaine, the free base. While the first is commonly administered by insufflation (‘snorting’) or intravenously, the second is adapted for inhalation (smoking). Cocaine can exert local anaesthetic action by inhibiting voltage-gated sodium channels, thus halting electrical impulse propagation; cocaine also impacts neurotransmission by hindering monoamine reuptake, particularly dopamine, from the synaptic cleft. The excess of available dopamine for postsynaptic activation mediates the pleasurable effects reported by users and contributes to the addictive potential and toxic effects of the drug. Cocaine is metabolised (mostly hepatically) into two main metabolites, ecgonine methyl ester and benzoylecgonine. Other metabolites include, for example, norcocaine and cocaethylene, both displaying pharmacological action, and the last one constituting a biomarker for co-consumption of cocaine with alcohol. This review provides a brief overview of cocaine’s prevalence and patterns of use, its physical-chemical properties and methods for analysis, pharmacokinetics, pharmacodynamics, and multi-level toxicity.

Investigating the Cocaine-induced Reduction of Potassium Current on the Generation of Action Potentials Using a Computational Model

Introduction

Drugs of abuse, such as cocaine, affect different brain regions and lead to pathological memories. These abnormal memories may occur due to changes in synaptic transmissions or variations in synaptic properties of neurons. It has been shown that cocaine inhibits delayed rectifying potassium currents in affected brain regions and can create pathological memories.This study investigates how the change in the conductance of delayed rectifying potassium channels can affect the produced action potentials using a computational model.

Methods

We present a computational model with different channels and receptors, including sodium, potassium, calcium, NMDARs, and AMPARs, which can produce burst-type action potentials. In the simulations, by changing the delayed rectifying potassium conductance bifurcation diagram is calculated.

Results

By decreasing the potassium current for a fixed stimulatory signal, burst-type action potentials can be generated. In the following and with a further reduction of potassium conductance, produced action potentials exhibit non-linear and even chaotic behaviors.

Conclusion

Results show that for a specific range of potassium conductance, a chaotic regime emerges in produced action potentials. These chaotic oscillations may play a role in inducing abnormal memories.

Highlights

Cocaine consumption reduces the potassium current in affected cells.Decreasing the potassium currents elicits burst action potentials.Produced bursts might have chaotic behaviors.Chaotic oscillations might be related to the toxic effects of cocaine.

Plain Language Summary

Drugs of abuse such as cocaine can manipulate brain circuits and may form some pathological memories. These memories can lead to long-term addiction. Furthermore, these drugs also can have toxic effects on the cells. Researchers are looking for the mechanisms that can lead to abnormal memories and toxic effects of drugs. It seems that an efficient mechanism that can be used by drugs of abuse is the manipulation of potassium currents in the affected cells. Here, in a computational model, we have shown that changes in the conductance of delayed rectifying potassium channels can lead to nonlinear and even chaotic behaviors in the produced action potentials. These behaviors might have a role in drug toxic effects.

Substance-Induced Psychoses: An Updated Literature Review

Background: On the current psychopharmacological panorama, the variety of substances able to provoke an episode of acute psychosis is rapidly increasing. Such psychotic episodes are classified according to the major category of symptoms: positive, negative, or cognitive psychotic episodes. On one hand, the abuse of methamphetamines, cannabis, and cocaine plays a big role in increasing the incidence of episodes resembling a psychotic disorder. On the other hand, the progress in terms of pharmacodynamics knowledge has led to the synthesis of new drugs, such as cannabinoids and cathinone's, which have rapidly entered into the common pool of abusers' habits. Regarding these newly synthesized substances of abuse, further clinical studies are needed to understand their psychogenic properties. The topic of this review is complicated due to the frequent abuse of psychotomimetic drugs by patients affected by psychotic disorders, a fact that makes it extremely difficult to distinguish between an induced psychosis and a re-exacerbation of a previously diagnosed disorder. Methods: The present narrative review summarizes results from clinical studies, thus investigating the psychotogenic properties of abused substances and the psychotic symptoms they can give rise to. It also discusses the association between substance abuse and psychosis, especially with regards to the differential diagnosis between a primary vs. a substance-induced psychotic disorder. Findings: Our findings support the theory that psychosis due to substance abuse is commonly observed in clinical practice. The propensity to develop psychosis seems to be a function of the severity of use and addiction. Of note, from a phenomenological point of view, it is possible to identify some elements that may help clinicians involved in differential diagnoses between primary and substance-induced psychoses. There remains a striking paucity of information on the outcomes, treatments, and best practices of substance-induced psychotic episodes.

Oxidative Stress and Cocaine Intoxication as Start Points in the Pathology of Cocaine-Induced Cardiotoxicity

Psychomotor stimulants are the most commonly used prohibited substances after cannabis. Globally, their use reaches epidemiological proportions and is one of the most common causes of death in many countries. The use of illicit drugs has negative effects on the cardiovascular system and is one of the causes of serious cardiovascular pathologies, ranging from abnormal heart rhythms to heart attacks and sudden cardiac death. The reactive oxygen species generation, toxic metabolites formation, and oxidative stress play a significant role in cocaine-induced cardiotoxicity. The aim of the present review is to assess acute and chronic cocaine toxicity by focusing on the published literature regarding oxidative stress levels. Hypothetically, this study can serve as a basis for developing a rapid and effective method for determining oxidative stress levels by monitoring changes in the redox status of patients with cocaine intoxication.

Computational Design and Crystal Structure of a Highly Efficient Benzoylecgonine Hydrolase

Benzoylecgonine (BZE) is the major toxic metabolite of cocaine and is responsible for the long-term cocaine-induced toxicity owing to its long residence time in humans. BZE is also the main contaminant following cocaine consumption. Here, we identified the bacterial cocaine esterase (CocE) as a BZE-metabolizing enzyme (BZEase), which can degrade BZE into biological inactive metabolites (ecgonine and benzoic acid). CocE was redesigned by a reactant-state-based enzyme design theory. An encouraging mutant denoted as BZEase2, presented a >400-fold improved catalytic efficiency against BZE compared with wild-type (WT) CocE. In vivo, a single dose of BZEase2 (1 mg kg^-1 , IV) could eliminate nearly all BZE within only two minutes, suggesting the enzyme has the potential for cocaine overdose treatment and BZE elimination in the environment by accelerating BZE clearance. The crystal structure of a designed BZEase was also determined.

"I Can't Move My Arms and Legs": A Rare Cause of Hypokalemia-Induced Quadriparesis

Hypokalemia is a relatively common electrolyte abnormality in hospitalized patients. Severe hypokalemia (<2.5 mEq/L) can lead to profound muscle weakness or paralysis, especially in the setting of acute onset of hypokalemia. Multiple mechanisms of hypokalemia have been described, such as decreased potassium intake, increased losses, and increased transcellular shift of potassium. Drugs can rarely cause hypokalemia by one of the above-mentioned mechanisms. Here, we report a case of cocaine use leading to severe hypokalemia manifesting as quadriparesis. The aggressive repletion of potassium led to a complete resolution of muscular weakness.

Cocaine induced heart failure: report and literature review

Heart failure is a complex clinical syndrome associated with high mortality and morbidity, creating a major public healthcare problem. It has a variety of etiologies, including substance abuse. Cocaine-induced cardiotoxicity is caused by direct effects of inhibition of sodium channels and indirect effects by inhibiting catecholamine uptake leading to increased sympathetic activity. Management is through the cessation of cocaine use and implantation of guideline-directed medical therapy for heart failure with the exception of beta-blockers as their safe usage is still controversial due to the risk of the unopposed alpha-adrenergic activity. Dexmedetomidine (Precedex) and Benzodiazepines (i.e., midazolam) are options for patients that demonstrate signs and symptoms of acute cocaine intoxication. If the actions of benzodiazepines fail to achieve hemodynamic stability, nitroglycerin may be used (especially in patients with cocaine-associated chest pain and hypertension). Cardiac transplantation is recommended for those who have demonstrated severe cardiovascular disease from cocaine. We present a 43-year-old male with a long-standing history of cocaine use who developed cardiomyopathy and severe acute decompensated heart failure found to have an ejection fraction of <20% admitted to the intensive care unit. He required inotropic support with milrinone and mechanical ventilation. He was later extubated and then discharged with an outpatient evaluation for a cardiac transplant.

Cocaine Reduces Ciliary Beat Frequency of Human Nasal Epithelial Cells

BACKGROUND/AIM

Cocaine is a widely used recreational drug and is known for its nasal complications including epithelial, cartilage and bone damage. The aim of the study was to analyze the impact of cocaine on ciliary beat frequency (CBF) of human nasal epithelial cells and therefore better understand its side effects on nasal mucosa.

MATERIALS AND METHODS

Nasal epithelial cells of 21 healthy subjects were harvested and exposed in vitro to cocaine hydrochloride solutions ranging from 0.875% to 7%. High-speed video footage was acquired with phase contrast microscopy and CBF was analyzed with Sissons-Ammons Video Analysis (SAVA) software.

RESULTS

All tested concentrations led to a significant reduction in CBF compared to the control. Effects increased over time and with concentration. A mechanical inhibition of cilia by cocaine crystals was also observed.

CONCLUSION

We assume that CBF reduction is part of the pathomechanism leading to nasal complications in cocaine abuse. Considering these results, clinical usage of cocaine should be critically evaluated and restricted to select cases only.

Drugs of Abuse and Heart Failure

Substance use is common among those with heart failure (HF) and is associated with worse clinical outcomes. Alcohol, tobacco, cannabis, and cocaine are commonly abused substances that can contribute to the development and worsening of HF. Heavy alcohol consumption can lead to dilated cardiomyopathy, whereas moderate intake may decrease incident HF. Tobacco increases the risk of HF through coronary artery disease and coronary artery disease-independent mechanisms. Continued smoking worsens outcomes for those with HF and cessation is associated with an improved risk of major adverse cardiac events. Cannabis has complex interactions on the cardiovascular system depending on the method of consumption, amount consumed, and content of cannabinoids. Delta-9-tetrahydrocannabinol can increase sympathetic tone, cause vascular dysfunction, and may increase the risk of myocardial infarction. Cannabidiol is cardioprotective in preclinical studies and is a potential therapeutic target. Cocaine increases sympathetic tone and is a potent proarrhythmogenic agent. It increases the risk of myocardial infarction and can also lead to a dilated cardiomyopathy. The use of beta-blockers in those with HF and cocaine use is likely safe and effective. Future studies are needed to further elucidate the impact of these substances both on the development of HF and their effects on those who have HF.

Psychostimulant use and the brain

Psychostimulant users are typically young adults. We have conducted a narrative review of neuropsychiatric harms associated with the psychostimulants methamphetamine/amphetamine, cocaine and 3,4-methylenedioxymethamphetamine (MDMA), focusing on epidemiological factors, common clinical presentations, underlying causal mechanisms and treatment options. The major neuropsychiatric harms of psychostimulant use are stroke, neurocognitive impairment, Parkinson's disease, seizures and psychotic illness. These arise through a combination of acute monoamine release, longer-term neurotransmitter effects and indirect effects. These effects are moderated by factors in the individual and in the pattern of substance use. Neuropsychiatric harms associated with psychostimulant use can thus lead to severe long-term impairment.

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.

Acute and Chronic Effects of Cocaine on Cardiovascular Health

Cardiac complications resulting from cocaine use have been extensively studied because of the complicated pathophysiological mechanisms. This study aims to review the underlying cellular and molecular mechanisms of acute and chronic effects of cocaine on the cardiovascular system with a specific focus on human studies. Studies have consistently reported the acute effects of cocaine on the heart (e.g., electrocardiographic abnormalities, acute hypertension, arrhythmia, and acute myocardial infarction) through multifactorial mechanisms. However, variable results have been reported for the chronic effects of cocaine. Some studies found no association of cocaine use with coronary artery disease (CAD), while others reported its association with subclinical coronary atherosclerosis. These inconsistent findings might be due to the heterogeneity of study subjects with regard to cardiac risk. After cocaine use, populations at high risk for CAD experienced coronary atherosclerosis whereas those at low risk did not experience CAD, suggesting that the chronic effects of cocaine were more likely to be prominent among individuals with higher CAD risk. Studies also suggested that risky behaviors and cardiovascular risks may affect the association between cocaine use and mortality. Our study findings highlight the need for education regarding the deleterious effects of cocaine, and access to interventions for cocaine abusers.

Disease Modifiers of Inherited SCN5A Channelopathy

To date, a large number of mutations in SCN5A, the gene encoding the pore-forming α-subunit of the primary cardiac Na⁺ channel (Na_V1.5), have been found in patients presenting with a wide range of ECG abnormalities and cardiac syndromes. Although these mutations all affect the same Na_V1.5 channel, the associated cardiac syndromes each display distinct phenotypical and biophysical characteristics. Variable disease expressivity has also been reported, where one particular mutation in SCN5A may lead to either one particular symptom, a range of various clinical signs, or no symptoms at all, even within one single family. Additionally, disease severity may vary considerably between patients carrying the same mutation. The exact reasons are unknown, but evidence is increasing that various cardiac and non-cardiac conditions can influence the expressivity and severity of inherited SCN5A channelopathies. In this review, we provide a summary of identified disease entities caused by SCN5A mutations, and give an overview of co-morbidities and other (non)-genetic factors which may modify SCN5A channelopathies. A comprehensive knowledge of these modulatory factors is not only essential for a complete understanding of the diverse clinical phenotypes associated with SCN5A mutations, but also for successful development of effective risk stratification and (alternative) treatment paradigms.

Cocaine alters the mouse testicular epigenome with direct impact on histone acetylation and DNA methylation marks

RESEARCH QUESTION

Recent evidence suggests that cocaine administration in animal models can trigger non-genetic inheritance of addiction traits from father to offspring, affecting development and behaviour. Is chronic cocaine intake involved in alterations of epigenetic homeostasis in the testis?

DESIGN

Epigenetic marks and mediators in testis and isolated germ cells of adult mice treated with cocaine (10 mg/kg) or vehicle (sterile saline solution) were evaluated in an intermittent binge protocol: three intraperitoneal injections, 1 h apart, one day on/off for 13 days, collecting tissue 24 h after the last binge administration (day 14).

RESULTS

It was shown that chronic cocaine intake in mice disrupts testicular epigenetic homeostasis, increasing global methylated cytosine levels in DNA from germ cells and sperm. Cocaine also increased testicular and germ cell acetylated histone 3 and 4 and decreased expression of histone deacetylases HDAC1/2. Immunolocalization studies showed that HDAC1/2 and acetylated histone 3 and 4 proteins localize to meiotic germ cells. Analysis of mRNA expression in isolated germ cells shows decreased levels of Hdac1/2/8, Dnmt3b and Tet1 and increased levels of Dnmt3a gene expression after cocaine treatment.

CONCLUSIONS

Cocaine intake is associated with testicular toxicity and significant reproductive function impairment. The results presented here broaden the basic knowledge of the impact of addictive stimulants on testicular pathophysiology, fertility and male reproductive health and imply that altered epigenetic homeostasis by cocaine may have potential consequences on future generations.

Cellular and molecular responses to acute cocaine treatment in neuronal-like N2a cells: potential mechanism for its resistance in cell death

Cocaine is a highly abused drug that causes psychiatric and neurological problems. Its entry into neurons could alter cell-biochemistry and contribute in the manifestation of early pathological symptoms. We have previously shown the acute cocaine effects in rat C6 astroglia-like cells and found that these cells were highly sensitive to cocaine in terms of manifesting certain pathologies known to underlie psychological disorders. The present study was aimed to discern acute cocaine effects on the early onset of various changes in Neuro-2a (N2a) cells. Whole-cell patch-clamp recording of differentiated cells displayed the functional voltage-gated Na⁺ and K⁺ channels, which demonstrated the neuronal characteristics of the cells. Treatment of these cells with acute cocaine (1 h) at in vivo (nM to μM) and in vitro (mM) concentrations revealed that the cells remained almost 100% viable. Cocaine administration at 6.25 μM or 4 mM doses significantly reduced the inward currents but had no significant effect on outward currents, indicating the Na⁺ channel-blocking activity of cocaine. While no morphological change was observed at in vivo doses, treatment at in vitro doses altered the morphology, damaged the neurites, and induced cytoplasmic vacuoles; furthermore, general mitochondrial activity and membrane potential were significantly decreased. Mitochondrial dysfunction enabled the cells switch to anaerobic glycolysis, evidenced by dose-dependent increases in lactate and H₂S, resulting unaltered ATP level in the cells. Further investigation on the mechanism of action unfolded that the cell's resistance to cocaine was through the activation of nuclear factor E2-related factor-2 (Nrf-2) gene and subsequent increase of antioxidants (glutathione [GSH], catalase and GSH peroxidase [GPx]). The data clearly indicate that the cells employed a detoxifying strategy against cocaine. On a broader perspective, we envision that extrapolating the knowledge of neuronal resistance to central nervous system (CNS) diseases could delay their onset or progression.

Comprehensive review of cardiovascular toxicity of drugs and related agents

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

Pharmacological profile of methylphenidate-based designer drugs

BACKGROUND

Methylphenidate-based designer drugs are new psychoactive substances (NPS) that are used outside medical settings and their pharmacology is largely unexplored. The aim of the present study was to characterize the pharmacology of methylphenidate-based substances in vitro.

METHODS

We determined the potencies of the methylphenidate-based NPS N-benzylethylphenidate, 3,4-dichloroethylphenidate, 3,4-dichloromethylphenidate, ethylnaphthidate, ethylphenidate, 4-fluoromethylphenidate, isopropylphenidate, 4-methylmethylphenidate, methylmorphenate, and propylphenidate and the potencies of the related compounds cocaine and modafinil with respect to norepinephrine, dopamine, and serotonin transporter inhibition in transporter-transfected human embryonic kidney 293 cells. We also investigated monoamine efflux and monoamine receptor and transporter binding affinities. Furthermore, we assessed the cell integrity under assay conditions.

RESULTS

All methylphenidate-based substances inhibited the norepinephrine and dopamine transporters 4 to >1000-fold more potently than the serotonin transporter. Similar to methylphenidate and cocaine, methylphenidate-based NPS did not elicit transporter-mediated efflux of monoamines. Besides binding to monoamine transporters, several test drugs had affinity for adrenergic, serotonergic, and rat trace amine-associated receptors but not for dopaminergic or mouse trace amine-associated receptors. No cytotoxicity was observed after drug treatment at assay concentrations.

CONCLUSION

Methylphenidate-based substances had pharmacological profiles similar to methylphenidate and cocaine. The predominant actions on dopamine transporters vs. serotonin transporters may be relevant when considering abuse liability. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

The Cardiovascular Effects of Cocaine

Cocaine is the leading cause for drug-abuse-related visits to emergency departments, most of which are due to cardiovascular complaints. Through its diverse pathophysiological mechanisms, cocaine exerts various adverse effects on the cardiovascular system, many times with grave results. Described here are the varied cardiovascular effects of cocaine, areas of controversy, and therapeutic options.

Vascular disease in cocaine addiction

Cocaine, a powerful vasoconstrictor, induces immune responses including cytokine elevations. Chronic cocaine use is associated with functional brain impairments potentially mediated by vascular pathology. Although the Crack-Cocaine epidemic has declined, its vascular consequences are increasingly becoming evident among individuals with cocaine use disorder of that period, now aging. Paradoxically, during the period when prevention efforts could make a difference, this population receives psychosocial treatment at best. We review major postmortem and in vitro studies documenting cocaine-induced vascular toxicity. PubMed and Academic Search Complete were used with relevant terms. Findings consist of the major mechanisms of cocaine-induced vasoconstriction, endothelial dysfunction, and accelerated atherosclerosis, emphasizing acute, chronic, and secondary effects of cocaine. The etiology underlying cocaine's acute and chronic vascular effects is multifactorial, spanning hypertension, impaired homeostasis and platelet function, thrombosis, thromboembolism, and alterations in blood flow. Early detection of vascular disease in cocaine addiction by multimodality imaging is discussed. Treatment may be similar to indications in patients with traditional risk-factors, with few exceptions such as enhanced supportive care and use of benzodiazepines and phentolamine for sedation, and avoiding β-blockers. Given the vascular toxicity cocaine induces, further compounded by smoking and alcohol comorbidity, and interacting with aging of the crack generation, there is a public health imperative to identify pre-symptomatic markers of vascular impairments in cocaine addiction and employ preventive treatment to reduce silent disease progression.

Magnetic Lateral Flow Strip for the Detection of Cocaine in Urine by Naked Eyes and Smart Phone Camera

Magnetic lateral flow strip (MLFS) based on magnetic bead (MB) and smart phone camera has been developed for quantitative detection of cocaine (CC) in urine samples. CC and CC-bovine serum albumin (CC-BSA) could competitively react with MB-antibody (MB-Ab) of CC on the surface of test line of MLFS. The color of MB-Ab conjugate on the test line relates to the concentration of target in the competition immunoassay format, which can be used as a visual signal. Furthermore, the color density of the MB-Ab conjugate can be transferred into digital signal (gray value) by a smart phone, which can be used as a quantitative signal. The linear detection range for CC is 5–500 ng/mL and the relative standard deviations are under 10%. The visual limit of detection was 5 ng/mL and the whole analysis time was within 10 min. The MLFS has been successfully employed for the detection of CC in urine samples without sample pre-treatment and the result is also agreed to that of enzyme-linked immunosorbent assay (ELISA). With the popularization of smart phone cameras, the MLFS has large potential in the detection of drug residues in virtue of its stability, speediness, and low-cost.

Cocaine Use in the Infertile Male Population: A Marker for Conditions Resulting in Subfertility

INTRODUCTION

We sought to evaluate the incidence and effect of cocaine use in the infertile male population.

MATERIALS AND METHODS

Men presenting for fertility evaluation reporting cocaine usage were identified via prospectively collected database. Data were analyzed for usage patterns, reproductive history, associated drug use and medical conditions, hormonal and semen parameters.

RESULTS

Thirty-eight out of 4,400 (0.9%) men reported cocaine use. Most used cocaine every 3 months or less. Compared with non-cocaine using men, cocaine users reported more recreational drug use (89 vs. 9.2%), marijuana use (78.9 vs. 11.4%), chlamydia (10.5 vs. 3%), herpes (7.9 vs. 2.5%), and tobacco use (55.3 vs. 19.5%). After excluding men with causes for azoospermia, the mean semen parameters for cocaine users were: volume 2.47 ± 1.02 ml; concentration 53.55 ± 84.04 × 10(6)/ml; motility 15.72 ± 12.26%; total motile sperm count 76.67 ± 180.30 × 10(6).

CONCLUSIONS

Few (< 1%) men in our infertile population reported the use of cocaine, and the frequency of use was low. Given the low use rates and limitations of reporting bias, it is difficult to determine the direct effect of cocaine use on male fertility. However, while infrequent cocaine use seems to have limited impact on semen parameters, men reporting cocaine use represent a different cohort of men than the overall infertile population, with higher rates of concurrent substance abuse, tobacco use and infections, all of which may negatively impact their fertility. Reported cocaine users should be screened for concurrent drug use and infections.

Cardiac depression induced by cocaine or cocaethylene is alleviated by lipid emulsion more effectively than by sulfobutylether-β-cyclodextrin

OBJECTIVES

Cocaine intoxication leads to over 500,000 emergency department visits annually in the United States and ethanol cointoxication occurs in 34% of those cases. Cardiotoxicity is an ominous complication of cocaine and cocaethylene overdose for which no specific antidote exists. Because infusion of lipid emulsion (Intralipid) can treat lipophilic local anesthetic toxicity and cocaine is an amphipathic local anesthetic, the authors tested whether lipid emulsion could attenuate cocaine cardiotoxicity in vivo. The effects of lipid emulsion were compared with the metabolically inert sulfobutylether-β-cyclodextrin (SBE-β-CD; Captisol) in an isolated heart model of cocaine and cocaethylene toxicity to determine if capture alone could exert similar benefit as lipid emulsion, which exhibits multimodal effects. The authors then tested if cocaine and cocaethylene, like bupivacaine, inhibit lipid-based metabolism in isolated cardiac mitochondria.

METHODS

For whole animal experiments, Sprague-Dawley rats were anesthetized, instrumented, and pretreated with lipid emulsion followed by a continuous infusion of cocaine to assess time of onset of cocaine toxicity. For ex vivo experiments, rat hearts were placed onto a nonrecirculating Langendorff system perfused with Krebs-Henseleit solution. Heart rate, left ventricle maximum developed pressure (LVdevP), left ventricle diastolic pressure, maximum rate of contraction (+dP/dtmax), maximum rate of relaxation (-dP/dtmax), rate-pressure product (RPP = heart rate × LVdevP), and line pressure were monitored continuously during the experiment. A dose response to cocaine (10, 30, 50, and 100 μmol/L) and cocaethylene (10, 30, and 50 μmol/L) was generated in the absence or presence of either 0.25% lipid emulsion or SBE-β-CD. Substrate-specific rates of oxygen consumption were measured in interfibrillar cardiac mitochondria in the presence of cocaine, cocaethylene, ecgonine, and benzoylecgonine.

RESULTS

Treatment with lipid emulsion delayed onset of hypotension (140 seconds vs. 279 seconds; p = 0.008) and asystole (369 seconds vs. 607 seconds; p = 0.02) in whole animals. Cocaine and cocaethylene induced dose-dependent decreases in RPP, +dP/dtmax, and -dP/dtmaxabs (p < 0.0001) in Langendorff hearts; line pressure was increased by cocaine and cocaethylene infusion, but not altered by treatment. Lipid emulsion attenuated cocaine- and cocaethylene-induced cardiac depression. SBE-β-CD alone evoked a mild cardiodepressant effect (p < 0.0001) but attenuated further cocaine- and cocaethylene-induced decrements in cardiac contractility at high concentrations of drug (100 μmol/L; p < 0.001). Finally, both cocaine and cocaethylene, but not ecgonine and benzoylecgonine, inhibited lipid-dependent mitochondrial respiration by blocking carnitine exchange (p < 0.05).

CONCLUSIONS

A commercially available lipid emulsion was able to delay progression of cocaine cardiac toxicity in vivo. Further, it improved acute cocaine- and cocaethylene-induced cardiac toxicity in rat isolated heart while SBE-β-CD was effective only at the highest cocaine concentration. Further, both cocaine and cocaethylene inhibited lipid-dependent mitochondrial respiration. Collectively, this suggests that scavenging-independent effects of lipid emulsion may contribute to reversal of acute cocaine and cocaethylene cardiotoxicity, and the beneficial effects may involve mitochondrial lipid processing.

Neurologic Complications of Psychomotor Stimulant Abuse

Psychomotor stimulants are drugs that act on the central nervous system (CNS) to increase alertness, elevate mood, and produce a sense of well-being. These drugs also decrease appetite and the need for sleep. Stimulants can enhance stamina and improve performance in tasks that have been impaired by fatigue or boredom. Approved therapeutic applications of stimulants include attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. These agents also possess potent reinforcing properties that can result in excessive self-administration and abuse. Chronic use is associated with adverse effects including psychosis, seizures, and cerebrovascular accidents, though these complications usually occur in individuals with preexisting risk factors. This chapter reviews the adverse neurologic consequences of chronic psychomotor stimulant use and abuse, with a focus on two prototypical stimulants methamphetamine and cocaine.

Cocaine use and risk of stroke: a systematic review

BACKGROUND

Both cocaine use and strokes impact public health. Cocaine is a putative cause of strokes, but no systematic review of the scientific evidence has been published.

METHODS

All relevant bibliographic-databases were searched until January 2014 for articles on the epidemiological association between cocaine use and strokes. Search strings were supervised by expert librarians. Three researchers independently reviewed studies for inclusion and data extraction following STROBE recommendations. Quality appraisal included study validity and bias. Both ischemic and hemorrhagic strokes were considered.

RESULTS

Of 996 articles, 9 were selected: 7 case-control studies (CCS) and 2 cross-sectional (CSS) studies. One CCS (aOR=6.1; 95% CI: 3.3-11.8) and one CSS (aOR=2.33; 95% CI: 1.74-3.11) showed an association between cocaine and hemorrhagic strokes. The latter study also found a positive relationship with ischemic stroke (aOR=2.03; 95% CI: 1.48-2.79). Another CCS found the exposure to be associated with stroke without distinguishing between types (aOR=13.9; 95% CI: 2.8-69.4). One forensic CCS found that deaths with cocaine-positive toxicology presented a 14.3-fold (95% CI: 5.6-37) and 4.6-fold (95% CI: 2.5-8.5) increased risk of atherosclerosis compared to opioid-related deaths and hanging-deaths respectively. One CCS did not provide an aOR but found a statistically significant association between cocaine and hemorrhagic stroke. Three CCS and one CSS did not find any relationship between cocaine and strokes. Inadequate control for confounding was not uncommon.

CONCLUSIONS

Epidemiological evidence suggests that cocaine use increases the risk of stroke. Larger, more rigorous observational studies, including cohort approaches, are needed to better quantify this risk, and should consider stroke type, hypertension variation, frequency/length of cocaine use, amphetamines co-use, and other factors.

Effects of cocaine on the hypothalamic-pituitary-adrenal axis

INTRODUCTION

Cocaine hydrochloride is a psychoactive substance extracted from the leaves of plants called Erythroxylum coca. Cocaine is the second most commonly used drug in the world after cannabis; 20 % of cocaine users will become long-term cocaine-dependent patients. Different routes of administration may be recognized: smokable modality, intranasal and intravenous. Cocaine is a potent stimulant of the sympathetic nervous system and causes structural changes on the brain, heart, lung, liver and kidney. It has long been known that use of cocaine may produce alterations to the endocrine system. Research on behavioral and neuroendocrine effects of cocaine dates back several years ago and has increasingly focused on alterations of the hypothalamic-pituitary-adrenal (HPA) axis, which appears to be the chief target of cocaine effects.

STUDIES

Animal (mainly rats and monkeys) and human studies have clearly shown a close relation between cocaine consumption and overdrive of the HPA axis. Such activation is likely involved, though via a still undefined mechanism, in the behavioral and cardiovascular changes of drug abusers as well as in the reinforcement/relapse phenomena. Further studies of the pathophysiology of cocaine addicts will help to devise new therapeutic strategies for these patients.

Supported core–shell nanobiosensors for quantitative fluorescence imaging of extracellular pH

“Click” chemistry was used to functionalize silica substrates with pH-sensitive nanoparticles, thus producing uniform and highly luminescent ion-sensitive surfaces for quantitative and spatially-resolved extracellular measurements on live cells.

Effects of an epilepsy-causing mutation in the SCN1A sodium channel gene on cocaine-induced seizure susceptibility in mice

RATIONALE

High doses of cocaine can elicit seizures in humans and in laboratory animals. Several mechanisms have been proposed for the induction of seizures by cocaine, including enhanced monoaminergic signaling, blockade of ion channels, and alterations in GABA and glutamate transmission. Mutations in the SCN1A gene, which encodes the central nervous system (CNS) voltage-gated sodium channel (VGSC) Nav1.1, are responsible for several human epilepsy disorders including Dravet syndrome and genetic (generalized) epilepsy with febrile seizures plus (GEFS+). Mice heterozygous for the R1648H GEFS+ mutation (RH mice) exhibit reduced interneuron excitability, spontaneous seizures, and lower thresholds to flurothyl- and hyperthermia-induced seizures. However, it is unknown whether impaired CNS VGSC function or a genetic predisposition to epilepsy increases susceptibility to cocaine-induced seizures.

OBJECTIVES

Our primary goal was to determine whether Scn1a dysfunction caused by the RH mutation alters sensitivity to cocaine-induced behavioral and electrographic (EEG) seizures. We also tested novelty- and cocaine-induced locomotor activity and assessed the expression of Nav1.1 in midbrain dopaminergic neurons.

RESULTS

We found that RH mice had a profound increase in cocaine-induced behavioral seizure susceptibility compared to wild-type (WT) controls, which was confirmed with cortical EEG recordings. By contrast, although the RH mice were hyperactive in novel environments, cocaine-induced locomotor activity was comparable between the mutants and WT littermates. Finally, immunofluorescence experiments revealed a lack of Nav1.1 immunoreactivity in dopaminergic neurons.

CONCLUSION

These data indicate that a disease-causing CNS VGSC mutation confers susceptibility to the proconvulsant, but not motoric, effects of cocaine.

Cardiovascular toxicity of novel psychoactive drugs: lessons from the past

The long use of ephedrine, amphetamines, cocaine, LSD and more recently 3,4-methylenedioxy-N-methylamphetamine (MDMA; "Ecstasy") allows us to predict with some confidence what cardiovascular risks are likely to be associated with novel psychoactive substances (NPS). Once the probably multiple biological activities of a compound are known it is possible to define the likely risks of cardiovascular toxicity. Agonists of 5-HT(2A) receptors or alpha-adrenoceptors may cause vasoconstriction and tissue ischemia. Drugs which have agonist affinity for 5-HT(2B) receptors will probably promote heart valve fibrosis leading to heart failure. Compounds that interfere with uptake of dopamine or 5-hydroxytryptamine (5-HT) are likely to also have effects on noradrenergic neurotransmission and lead to sympathomimetic effects on the heart and vasculature. Drugs that cause dopamine release, or inhibit uptake are likely to be addictive and lead to chronic use. Other drugs (particularly the so-called empathogens) are associated with weekly usage in social settings; over time such use can lead to cardiovascular harm. Defining which of these effects NPS have is an important element of predicting the harm they may cause and informing those appointed to introduce regulations to control them.

Acute mountain sickness impact among travelers to Cusco, Peru

BACKGROUND

Increasing numbers of travelers are visiting high altitude locations in the Andes. The epidemiology of acute mountain sickness (AMS) among tourists to high altitude in South America is not well understood.

METHODS

A cross-sectional study to evaluate the epidemiology, pre-travel preparation, and impact of AMS among travelers to Cusco, Peru (3,400 m) was performed at Cusco's International Airport during June 2010. Foreign travelers, 18 years or older, staying 15 days or less, departing Cusco were invited to participate. Demographic, itinerary, and behavioral data were collected. The Lake Louise Clinical score (LLCS) was used to assess AMS symptoms.

RESULTS

In total, 991 travelers participated, median age 32 years (interquartile range 25-49), 55.5% female, 86.7% tourists, mostly from the United States (48.2%) and England (8.1%). Most (76.7%) flew from sea level to Cusco and 30.5% visited high altitude in the previous 2 months. Only 29.1% received AMS advice from a physician, 19% recalled advice on acetazolamide. Coca leaf products (62.8%) were used more often than acetazolamide (16.6%) for prevention. AMS was reported by 48.5% and 17.1% had severe AMS. One in five travelers with AMS altered their travel plans. Travelers older than 60 years, with recent high altitude exposure, who visited lower cities in their itinerary, or used acetazolamide were less likely to have AMS. Using coca leaf products was associated with increased AMS frequency.

CONCLUSIONS

AMS was common and adversely impacted plans of one in five travelers. Acetazolamide was associated with decreased AMS but was prescribed infrequently. Other preventive measures were not associated with a decrease in AMS in this population. Pre-travel preparation was suboptimal.

Bacterial cocaine esterase: a protein-based therapy for cocaine overdose and addiction

Cocaine is highly addictive and there are no pharmacotherapeutic drugs available to treat acute cocaine toxicity or chronic abuse. Antagonizing an inhibitor such as cocaine using a small molecule has proven difficult. The alternative approach is to modify cocaine's pharmacokinetic properties by sequestering or hydrolyzing it in serum and limiting access to its sites of action. We took advantage of a bacterial esterase (CocE) that has evolved to hydrolyze cocaine and have developed it as a therapeutic that rapidly and specifically clears cocaine from the subject. Native enzyme was unstable at 37°C, thus limiting CocE's potential. Innovative computational methods based on the protein's structure helped elucidate its mechanism of destabilization. Novel protein engineering methodologies were applied to substantially improve its stability in vitro and in vivo. These improvements rendered CocE as a powerful and efficacious therapeutic to treat cocaine intoxication and lead the way towards developing a therapy for addiction.

Electrocardiographic findings associated with cocaine use in humans: a systematic review

Cocaine remains highly prevalent and accessible in the general population, continues to represent one of the most commonly reported substances in drug-related presentations to emergency departments, and is frequently implicated in drug-related deaths. Fatal cardiac arrhythmias are often suspected in the latter cases. In spite of this, its complex effects on the human cardiac conduction system remain poorly elucidated. In this article we sought to systematically review the medical literature to identify the electrocardiographic findings that have been linked to cocaine use in humans in an effort to highlight what physicians can expect to encounter when managing patients using the drug. The evidence is discussed, common findings are emphasized and clinical recommendations are proposed.

Putting cocaine use and cocaine-associated cardiac arrhythmias into epidemiological and clinical perspective

This is the first article in a series of three articles on cocaine-related cardiac arrhythmias, following on from the 2008 British Pharmacological Society Winter Meeting Clinical Section Symposium entitled 'Cocaine induced cardiac arrhythmias - from ion channel to clinical treatment'. We will summarize the epidemiology of cocaine use across the world and in particular will focus on UK, Europe and US use prevalence data. We will discuss the acute cardiac and non-cardiac toxicity associated with cocaine and highlight the lack of data on the true UK prevalence of acute cocaine toxicity and on the incidence of cocaine-related cardiac arrhythmias.

Treatment of patients with cocaine-induced arrhythmias: bringing the bench to the bedside

Widespread use of cocaine and its attendant toxicity has produced a wealth of benchwork studies and small animal investigations that evaluated the effects of cocaine on the cardiovascular system. Despite this wealth of knowledge, very little is known about the frequency or types of arrhythmias in patients with significant cocaine toxicity. The likely aetiologies; catecholamine excess, sodium channel blockade, potassium channel blockade, calcium channel effects, or ischaemia may act alone or in concert to produce a vast array of clinical findings that are modulated by hyperthermia, acidosis, hypoxia and electrolyte abnormalities. The initial paper in the series by Wood & Dargan providing the epidemiological framework of cocaine use and abuse is followed by a detailed review of the electrophysiological effects of cocaine by O'Leary & Hancox. This review is designed to complement the previous papers and focuses on the diagnosis and treatment of patients with cocaine-associated arrhythmias.