Cocaine, ethanol, and cocaethylene cardiotoxity in an animal model of cocaine and ethanol abuse

Cocaethylene: When Cocaine and Alcohol Are Taken Together

Cocaine is taken frequently together with ethanol and this combination produces a psychoactive metabolite called cocaethylene which has similar properties to the parent drug and may be more cardiotoxic. Cocaethylene has a longer half-life than cocaine, so that people who combine cocaine and ethanol may experience a longer-lasting, as well as more intense, psychoactive effect. Cocaethylene is the only known instance where a new psychoactive substance is formed entirely within the body. Although known to science for decades, cocaethylene has not been extensively studied and even its metabolic pathways are not entirely elucidated. Like its parent drug, cocaethylene blocks the reuptake of dopamine and increases post-synaptic neuronal activity; the parent drug may also block reuptake of serotonin as well. Cocaethylene has been studied in animal models in terms of its pharmacology and its potential neurological effects. Since the combination of cocaine and alcohol is commonly used, it is important for clinicians to be aware of cocaethylene, its role in prolonging or intensifying cocaine intoxication, and how it may exacerbate cocaine-induced cardiovascular disorders. Most cardiac-related risk assessment tools do not ask about cocaine use, which can prevent clinicians from making optimal therapeutic choices. Greater awareness of cocaethylene is needed for clinicians, and those who use cocaine should also be aware of the potential for polysubstance use of cocaine and ethanol to produce a potentially potent and long-lasting psychoactive metabolite.

Alcohol and Cocaine Combined Substance Use on Adult Hypothalamic Neural Stem Cells and Neurogenesis

Many advancements have been made over the years looking at the individual and combined effects of drugs of abuse on the brain, with one key area of research focusing on the effects on neurogenesis. An integral part of fetal brain development and, later, maintenance in the adult brain, neurogenesis occurs in three main regions: subventricularzone of the lateral ventricles (SVZ), subgranularzone of the dentate gyrus (SGZ), and the tanycyte layer in the hypothalamus (TL). We will review current literature on combined drugs of abuse and their effect on adult neurogenesis. More specifically, this review will focus on the effect of combining cocaine and alcohol. Additionally, the tanycyte layer will be explored in more depth and probed to look at the neurogenic properties of tanycytes and their role in neurogenesis.

Post-mortem toxicology in young sudden cardiac death victims: a nationwide cohort study

Aims

Several drugs increase the risk of ventricular fibrillation and sudden cardiac death (SCD). We aimed to investigate in detail the toxicological findings of all young SCD throughout Denmark.

Methods and results

Deaths in persons aged 1-49 years were included over a 10-year period. Death certificates and autopsy reports were retrieved and read to identify cases of sudden death and establish cause of death. All medico-legal autopsied SCD were included and toxicological reports collected. Positive toxicology was defined as the presence of any substance (licit and/or illicit). All toxicological findings had previously been evaluated not to have caused the death (i.e. lethal concentrations were excluded). We identified 620 medico-legal autopsied cases of SCD, of which 77% (n = 477) were toxicologically investigated post-mortem, and 57% (n = 270) had a positive toxicology profile. Sudden cardiac death with positive toxicology had higher rates of sudden arrhythmic death syndrome (SADS), compared with SCD with negative toxicology (56% vs. 42%, P < 0.01). In total, 752 agents were detected, and polypharmacy (defined as the presence of more than one drug) was present in 61% (n = 164), all substances combined. Psychotropic drugs were the most frequent (62%, n = 467), and 82% (n = 385) were in pharmacological or subpharmacological levels.

Conclusion

We found that more than half of all toxicologically investigated SCD victims have positive post-mortem toxicological findings, and polypharmacy is displayed in a considerable proportion. SCD with positive toxicology had higher rate of SADS, suggesting that the compounds may play a proarrhythmic role in these cases.

Rapid Separation and Quantitation of Cocaine and its Metabolites in Human Serum by Differential Mobility Spectrometry-tandem Mass Spectrometry (DMS-MS-MS)

Cocaine continues to be one of the most widespread abused illicit drugs in the USA. Rapid methods are needed for the identification and quantitation of cocaine and its metabolites, benzoylecgonine (BE), ecgonine methyl ester (EME) and cocaethylene (CE), in biological specimens by clinical and forensic toxicology laboratories. Presented is a differential ion mobility spectrometry-tandem mass spectrometry (DMS-MS-MS) method for the analysis of cocaine and its major metabolites in human serum that requires minimal sample preparation and no column chromatography. A Shimadzu Nexera X2 ultra-high performance liquid chromatography system was used to infuse the samples into the DMS cell at a rate of 30 μL/min. Separation of cocaine and its metabolites were performed in a SelexION DMS component from Sciex coupled to a QTRAP 6500 with an IonDrive Turbo V source for TurbolonSpray® using acetonitrile as a chemical modifier. Analysis consisted of ramping the CoV from -35 V to -6 V while monitoring the multiple reaction monitoring (MRM) transitions of each analyte. The assay was evaluated for linearity, bias, precision, carryover, interferences and stability. Calibration curves ranged from 10 to 1,000 ng/mL with linear regression correlation coefficients (r2) of 0.9912 or greater for each analyte. The limit of quantitation was set at 10 ng/mL. Intra-day precision (%CV) ranged from 0% to 15% for cocaine, 1% to 19% for BE, 1% to 17% for EME and 0% to 18% for CE. Inter-day precision ranged from 9% to 14% for cocaine, 2% to 17% for BE, 5% to 11% for EME and 5% to 15% for CE. No carryover or interferences were detected. Bland-Altman analysis of previously analyzed specimens by UPLC-MS-MS showed variability of 30% or less. The method demonstrates the applicability of DMS-MS-MS for high throughout analysis of drugs and their metabolites in clinical and forensic toxicology laboratories.

TV-1380 attenuates cocaine-induced changes in cardiodynamic parameters in monkeys and reduces the formation of cocaethylene

BACKGROUND

TV-1380 is a rationally mutated, human BChE fused to human serum albumin that has high hydrolytic enzymatic activity against cocaine and as well as an extended elimination half-life.

OBJECTIVE

The present studies examined the safety of TV-1380 and its protective effect when given to monkeys alone or concomitantly with cocaine and ethanol.

METHODS

A set of studies was conducted in monkeys with TV-1380. The parameters tested included telemetric assessment of cardiovascular parameters, clinical pathology, plasma analysis of cardiac troponin I, ex-vivo analyses of cocaethylene and PK analysis of serum concentrations of TV-1380, cocaine and its metabolites, and histopathological examinations.

RESULTS

TV-1380 treatment in monkeys was well tolerated. TV-1380 pretreatment prior to cocaine significantly attenuated the cardiac effects of cocaine and reduced cocaine-induced elevations in serum cardiac troponin I. TV-1380 changed the metabolic fate of cocaine resulting in decreased exposure to benzoylecgonine, while increasing the exposure to ecgonine methyl ester in plasma.TV-1380 reduced the plasma levels of the toxic metabolite cocaethylene formed after co-administration of ethanol and cocaine.

CONCLUSION

The results of this study demonstrate that TV-1380 not only accelerates the elimination of cocaine, but also protects the treated animal from the cardiac effects of cocaine, and inhibits the formation of the toxic cocaethylene metabolite when cocaine is given together with ethanol, supporting further clinical development of modified BChE products as possible treatments for cocaine abuse.

Ethanol addictively enhances the in vitro cardiotoxicity of cocaine through oxidative damage, energetic deregulation, and apoptosis

Cocaine (COC) is frequently consumed in polydrug abuse settings, and ethanol (EtOH) is the most prominent co-abused substance. Clinical data and experimental evidence suggest that the co-administration of COC with EtOH can be more cardiotoxic than EtOH or COC alone, but information on the molecular pathways involved is scarce. Since these data are crucial to potentiate the identification of therapeutic targets to treat intoxications, we sought to (i) elucidate the type of interaction that occurs between both substances, and (ii) assess the mechanisms implicated in the cardiotoxic effects elicited by COC combined with EtOH. For this purpose, H9c2 cardiomyocytes were exposed to COC (104 µM-6.5 mM) and EtOH (977 µM-4 M), individually or combined at a molar ratio based on blood concentrations of intoxicated abusers (COC 1: EtOH 9; 206 µM-110 mM). After 24 h, cell metabolic viability was recorded by the MTT assay and mixture toxicity expectations were calculated using the independent action (IA) and concentration addition (CA) models. EtOH (EC₅₀ 305.26 mM) proved to act additively with COC (EC₅₀ 2.60 mM) to significantly increase the drug in vitro cardiotoxicity, even when both substances were combined at individually non-cytotoxic concentrations. Experimental mixture testing (EC₅₀ 19.18 ± 3.36 mM) demonstrated that the cardiotoxicity was fairly similar to that predicted by IA (EC₅₀ 22.95 mM) and CA (EC₅₀ 21.75 mM), supporting additivity. Concentration-dependent increases of intracellular ROS/RNS and GSSG, depletion of GSH and ATP, along with mitochondrial hyperpolarization and activation of intrinsic, extrinsic, and common apoptosis pathways were observed both for single and combined exposures. In general, the mixture exhibited a toxicological profile that mechanistically did not deviate from the single drugs, suggesting that interventions such as antioxidant administration might aid in the clinical treatment of this type of polydrug intoxication. In a clinical perspective, the observed additive mixture effect may reflect the increased hazards at which users of this combination are exposed to in recreational settings.

Acute-onset heart failure secondary to long-standing abuse of alcohol, cocaine, and marijuana

Acute-onset heart failure in a young, otherwise healthy patient can be due to either acquired or congenital etiologies. While some diagnoses carry specific histologic hallmarks, many causes of myocardial injury culminate in the relatively nonspecific morphologic pattern of dilated cardiomyopathy. In such cases, a broad differential diagnosis and close clinicopathologic correlation are essential. Here we describe the acute and chronic histologic features of heart failure arising in the context of long-standing abuse of cocaine, alcohol, and marijuana. The mechanisms of cardiotoxicity are discussed for each drug, with particular emphasis on the amplified cardiac injury caused by concomitant cocaine and alcohol use. Although its histologic features are themselves nonspecific, correlation with clinical history, targeted studies to exclude alternative diagnoses, and careful morphologic examination permit confident diagnosis of cardiomyopathy secondary to polysubstance abuse.

Addictive drugs, arrhythmias, and cardiac inward rectifiers

In many addictive drugs including alcohol and nicotine, proarrhythmic effects were reported. This review provides an overview of the current knowledge in this field (with a focus on the inward rectifier potassium currents) to promote the lacking data and appeal for their completion, thus, to improve understanding of the proarrhythmic potential of addictive drugs.

Effects of ethanol on systemic hemodynamics in a porcine model of accidental hypothermia

OBJECTIVES

Accidental hypothermia is frequently associated with ethanol intoxication. Each has independent effects on systemic hemodynamics, but their combined effects are poorly understood. We aimed to describe the hemodynamic effects of ethanol intoxication in a model of severe hypothermia and rewarming.

METHODS

Anesthetized pigs was assigned to control (n=8) or ethanol groups (ETOH) (n=7, 3 mg/kg of ethanol via an orogastric tube). Subjects were cooled to 25°C using ice packs and then warmed to baseline core temperature with passive external and active core rewarming.

RESULTS

In the ETOH group, peak serum ethanol concentration was 202 mg/dL at 25°C. Ethanol had no effect on time of cooling or rewarming. In both the control and ETOH, there were similar maximal decreases in mean arterial pressure (from 94±24 to 50±15 mm Hg and 100±27 to 31±12 mm Hg, respectively), ventricular contractility (rate of maximal left ventricular pressure rise from 5731±1462 to 2610±596 mm Hg/s and 6832±1384 to 1937±437 mm Hg/s, respectively), and cardiac output (from 2.14±0.8 to 0.53±0.3 L/min and 2.93±0.9, to 0.44±0.2 L/min, respectively; all P<.001). After rewarming, only in the ETOH group were persistent decreases in mean arterial pressure (59±14 mm Hg), contractility (3982±1573 mm Hg/s), and cardiac output (1.6±0.9 L/min, all P<.03) observed.

CONCLUSIONS

Hypothermia caused significant adverse effects on cardiac function and systemic hemodynamics, which returned to baseline with rewarming. Ethanol intoxication had no additional effects on systemic hemodynamics during cooling; however, it caused more prolonged depression of cardiac function and adverse effects on systemic hemodynamics during rewarming. These data may have implications for resuscitation of ethanol-intoxicated victims of accidental hypothermia.

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.

Cocaine use disorders and acute myocardial infarction, excess length of hospital stay and overexpenditure

INTRODUCTION AND OBJECTIVES

To investigate the relationship between the prevalence of cocaine use disorders and acute myocardial infarction in patients aged ≥ 18 years and to estimate the influence of cocaine use disorders on mortality, excess length of stay, and overexpenditure among hospitalized patients with acute myocardial infarction.

METHODS

Retrospective study of the minimum basic data set of 87 Spanish hospitals from 2008 to 2010.

RESULTS

Among 5 575 325 admissions reviewed, there were 24 126 patients with cocaine use disorders and 79 076 cases of acute myocardial infarction. The incidence of acute myocardial infarction among patients with cocaine use disorders increased with age and reached a peak at 55 years to 64 years (P < .0001). Multivariate analysis showed that cocaine use disorders were more prevalent among patients with acute myocardial infarction independently of age, sex, other addictive disorders, and 30 other comorbidities (odds ratio = 3.0). Among patients with acute myocardial infarction, those with cocaine use disorders did not show an increase of in-hospital death, but did show excess length of hospital stay (1.5 days) and overexpenditure (382 euros).

CONCLUSIONS

Cocaine use disorders are associated with acute myocardial infarction and increase the length of hospital stay and overexpenditure among acute myocardial infarction patients. Cessation of cocaine use among these patients should be one of the primary therapeutic goals after hospital discharge.

Cocaine intoxication

Cocaine, a natural alkaloid derived from the coca plant, is one of the most commonly abused illicit drugs. Cocaine is commonly abused by inhalation, nasal insufflation, and intravenous injection, resulting in many adverse effects that ensue from local anesthetic, vasoconstrictive, sympathomimetic, psychoactive, and prothrombotic mechanisms. Cocaine can affect all body systems and the clinical presentation may primarily result from organ toxicity. Among the most severe complications are seizures, hemorrhagic and ischemic strokes, myocardial infarction, aortic dissection, rhabdomyolysis, mesenteric ischemia, acute renal injury and multiple organ failure.

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.

The ability of bacterial cocaine esterase to hydrolyze cocaine metabolites and their simultaneous quantification using high-performance liquid chromatography-tandem mass spectrometry

Cocaine toxicity is a widespread problem in the United States, responsible for more than 500,000 emergency department visits a year. There is currently no U.S. Food and Drug Administration-approved pharmacotherapy to directly treat cocaine toxicity. To this end, we have developed a mutant bacterial cocaine esterase (DM-CocE), which has been previously shown to rapidly hydrolyze cocaine into inert metabolites, preventing and reversing toxicity with limited immunogenic potential. Herein we describe the ability of DM-CocE to hydrolyze the active cocaine metabolites norcocaine and cocaethylene and its inability to hydrolyze benzoylecgonine. DM-CocE hydrolyzes norcocaine and cocaethylene with 58 and 45% of its catalytic efficiency for cocaine in vitro as measured by a spectrophotometric assay. We have developed a mass spectrometry method to simultaneously detect cocaine, benzoylecgonine, norcocaine, and ecgonine methyl ester to quantify the effect of DM-CocE on normal cocaine metabolism in vivo. DM-CocE administered to rats 10 min after a convulsant dose of cocaine alters the normal metabolism of cocaine, rapidly decreasing circulating levels of cocaine and norcocaine while increasing ecgonine methyl ester formation. Benzoylecgonine was not hydrolyzed in vivo, but circulating concentrations were reduced, suggesting that DM-CocE may bind and sequester this metabolite. These findings suggest that DM-CocE may reduce cocaine toxicity by eliminating active and toxic metabolites along with the parent cocaine molecule.

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

Cocaine is a highly active stimulant that alters dopamine metabolism in the central nervous system resulting in a feeling of euphoria that with time can lead to addictive behaviours. Cocaine has numerous deleterious effects in humans including seizures, vasoconstriction, ischaemia, increased heart rate and blood pressure, cardiac arrhythmias and sudden death. The cardiotoxic effects of cocaine are indirectly mediated by an increase in sympathomimetic stimulation to the heart and coronary vasculature and by a direct effect on the ion channels responsible for maintaining the electrical excitability of the heart. The direct and indirect effects of cocaine work in tandem to disrupt the co-ordinated electrical activity of the heart and have been associated with life-threatening cardiac arrhythmias. This review focuses on the direct effects of cocaine on cardiac ion channels, with particular focus on sodium, potassium and calcium channels, and on the contributions of these channels to cocaine-induced arrhythmias. Companion articles in this edition of the journal examine the epidemiology of cocaine use (Wood & Dargan) and the treatment of cocaine-associated arrhythmias (Hoffmann).

Patients with detectable cocaethylene are more likely to require intensive care unit admission after trauma

Cocaethylene (CE) is a toxic metabolite that is formed after simultaneous consumption of cocaine and ethanol. This potent stimulant is more toxic than cocaine and has a longer half-life. The deleterious hemodynamic and cardiovascular effects of CE have been proven in animal models. The aim of this study is to assess the impact of CE on clinical outcomes after trauma. We prospectively enrolled adult (≥13 years) trauma patients requiring admission. Predictor variables were age, sex, mechanism of injury, Injury Severity Score, base deficit, and toxicology groups (ethanol alone, cocaine alone, CE, and none). The outcomes examined were mortality, intensive care unit (ICU) admission, and length of hospital stay (LOS). We used nonparametric tests to compare continuous variables and χ² test to compare categorical data. We constructed a logistic regression to identify variables that could predict mortality and ICU admission. We enrolled 417 patients (74% male; 70% blunt injury; median age, 40 [range, 13-95]; overall mortality, 2.2%). Urine toxicology and serum ethanol level screens classified patients into the following groups: 13.4% ethanol only, 4.1% cocaine only, 8.9% CE, and 46% none. Mortality and LOS were not statistically different among the groups. In logistic regression analysis, none of the variables were statistically significant in predicting mortality. However, the presence of CE significantly increased the likelihood of ICU admission (odds ratio, 5.9; 95% confidence interval, 1.6-22). The presence of detectable CE in the urine does not increase the mortality or LOS in trauma patients requiring admission but does increase the likelihood of ICU admission.

Neurotoxic and cardiotoxic effects of cocaine and ethanol

INTRODUCTION

Concurrent abuse of alcohol and cocaine results in the formation of cocaethylene, a powerful cocaine metabolite. Cocaethylene potentiates the direct cardiotoxic and indirect neurotoxic effects of cocaine or alcohol alone.

CASE REPORT

A 44-year-old female with history of cocaine and alcohol abuse presented with massive stroke in the emergency department. CT scan revealed extensive left internal carotid artery dissection extending into the left middle and anterior cerebral arteries resulting in a massive left hemispheric infarct, requiring urgent decompressive craniectomy. The patient had a stormy hospital course with multiple episodes of torsades de pointes in the first 4 days requiring aggressive management. She survived all events and was discharged to a nursing home with residual right hemiplegia and aphasia.

CONCLUSION

The combination of ethanol and cocaine has been associated with a significant increase in the incidence of neurological and cardiac emergencies including cerebral infarction, intracranial hemorrhage, myocardial infarction, cardiomyopathy, and cardiac arrhythmias. The alteration of cocaine pharmacokinetics and the formation of cocaethylene have been implicated, at least partially, in the increased toxicity of this drug combination.

Concurrent cocaine and alcohol use in individuals presenting to an addiction treatment program

BACKGROUND

National population surveys and information from the National Drug Treatment Reporting System indicate cocaine use is increasing. There is a paucity of studies focusing on comorbid cocaine and alcohol use in Ireland.

AIMS

The aims of the study are to examine comorbid cocaine and alcohol use patterns in those under 45 years, presenting to a national addiction treatment unit for alcohol and drug dependence.

METHODS

A retrospective review of the substance misuse behavior of 465 individuals participating in an addiction rehabilitation programme for alcohol dependence.

RESULTS

Cocaine use among this population rose significantly between 1995 (8%) and 2006 (37.9%). There was a significant association between lifetime reported cocaine use and both psychotic disorders and deliberate self harm. Overall, the use was highest among younger age group and this declined steadily with age.

CONCLUSIONS

Cocaine use among the alcohol-dependent population is an increasing problem in the Republic of Ireland, and poses a problem of higher toxicity associated with concurrent cocaine and alcohol use.

Cocaine and ethanol: combined effects on coronary artery blood flow and myocardial function in dogs

OBJECTIVES

In combination, cocaine and ethanol are more cardiotoxic than is either substance alone. These substances together constitute a drug abuse combination that commonly results in fatality. Previously the authors have demonstrated that cardiotoxicity of cocaine and ethanol is in part due to synergistic myocardial-depressant effects. However, it remains unclear whether this myocardial depression is associated with concomitant adverse effects on coronary blood flow in relation to these substances. The aim of this study was to investigate combined effects of cocaine and ethanol on myocardial blood flow, in relation to indices of myocardial function.

METHODS

Anesthetized dogs were instrumented for hemodynamic monitoring with Doppler flow probes placed on the circumflex and left anterior descending (LAD) coronary arteries. Dogs were randomized to three groups (each n = 6): ethanol (E, 1.5 g/kg followed by placebo), cocaine (C, placebo followed by cocaine, 7.5 mg/kg IV), or cocaine plus ethanol (C + E). All measurements were made at control, after placebo or ethanol, and then at fixed time intervals after cocaine or placebo bolus over 3 hours.

RESULTS

In both the C + E and the C groups, circumflex blood flow (CBF) decreased by 71% (95% confidence interval [CI] = 56% to 85%) and 57% (95% CI = 43% to 72%, both p < 0.04 vs. baseline) immediately after cocaine bolus. This was associated with transient depression of cardiac output, myocardial contractile function, and rate-pressure product (RPP), all indices of myocardial oxygen demand. A subsequent rebound increase of coronary sinus blood flow (CSBF) of 56% (95% CI = 26% to 137%, p < 0.03) compared to baseline occurred only in the C group and was associated with increases of myocardial contractile function and RPP. In the C + E group, 2 hours after drug administration, there was a decrease in CSBF of 49% (95% CI = 32% to 67%; p < 0.01) compared to baseline, which was associated with concomitant numerical decreases of the indices of myocardial oxygen demand and accumulation of cocaethylene.

CONCLUSIONS

Acute decreases in myocardial flow secondary to cocaine, and cocaine and ethanol in combination, were similar and temporally associated with cocaine's direct myocardial-depressant effects. Rebound increases in myocardial function and blood flow due to cocaine were attenuated by ethanol. Delayed myocardial depression and decreases in myocardial blood flow were observed only with coadministration of cocaine and ethanol.

Polydrug use among club-going young adults recruited through time-space sampling

The Club Drugs and Health Project was supported by a grant from the National Institute on Drug Abuse (R01-DA014925-02, Jeffrey T. Parsons, Principal Investigator). Christian Grov was supported as a postdoctoral fellow in the Behavioral Sciences training in drug abuse research program sponsored by Public Health Solutions and the National Development and Research Institutes, Inc. (NDRI) with funding from the National Institute on Drug Abuse (T32 DA07233). The authors recognize the contributions of the Club Drug and Health Project team-Michael Adams, Virginia Andersen, Anthony Bamonte, Jessica Colon, Armando Fuentes, Sarit A. Golub, Chris Hietikko, Eda Inan, Juline Koken, Jose E. Nanin, Anthony Surace, Julia Tomassilli, Jon Weiser, Brooke E. Wells, and the recruitment team. An earlier version of this paper was presented at the 2008 meeting of the College on Problems of Drug Dependence (CPDD). Though some researchers have indicated club drug users are more likely to be polydrug users, there remains little known about the prevalence and specific combinations of the substances they use. Between 2004 and 2006, and using time-space sampling, a stratified sample of 400, 18-29-year-old New York City club-going, drug-using young adults were recruited into the Club Drugs and Health Project. Most participants (91.7%) had engaged in polydrug usage and 1,670 combinations of drugs were reported. Ecstasy (86.6% of users) and cocaine (85.7% of users) were the two most-frequently reported club drugs used in combination with other substances. In terms of poly-club drug combinations, ecstasy appeared to be the "universal compliment" as this drug was most often cited in combinations with other club drugs (specifically ecstasy + ketamine, ecstasy + cocaine, ecstasy + gamma hydroxybutyrate or GHB). Other frequently cited drug combinations included cocaine and marijuana, ecstasy and marijuana, LSD and marijuana, and cocaine and alcohol. These data highlight the need to develop drug health-education and prevention messages targeted at polydrug usage.

Pharmacodynamic evaluation of the cardiovascular effects after the coadministration of cocaine and ethanol

One of the most common drug dependencies occurring with alcoholism is cocaine dependence. This combination is particularly worrisome because of the increased risk of cardiovascular events associated with their coabuse. Although it is well known that ethanol increases the cardiovascular effects of cocaine by inhibiting cocaine clearance and the formation of cocaethylene, it has also been postulated that ethanol enhances the cardiovascular effects of cocaine independent of the two latter mechanisms. In this study, we investigated the cardiovascular pharmacodynamics of the cocaine-ethanol interaction to determine whether ethanol directly enhanced the cardiovascular effects of cocaine. Dogs (n = 6) were administered cocaine alone (3 mg/kg i.v.) and in combination with ethanol (1 g/kg i.v.) on separate study days. Blood pressure, heart rate, and the electrocardiogram were monitored continuously, and blood samples were collected periodically after drug administration. Concentration-time data were fitted to a two-compartment model, and concentration-effect data were fitted to a simple E(max) model using WinNonlin software. Pharmacokinetic and pharmacodynamic parameters were compared between the two treatment phases by a paired t test. The administration of ethanol before cocaine resulted in a decrease in cocaine clearance, but there were no differences in any of the other pharmacokinetic or pharmacodynamic parameter values between the cocaine alone and cocaine plus ethanol phases. As has been demonstrated in previous animal and human studies, the clearance of cocaine was decreased by prior administration of ethanol. However, ethanol did not change the concentration-effect relationship of the cardiovascular response to cocaine administration. It is concluded from this study that ethanol does not directly enhance the cardiovascular effects of cocaine.

Gender differences with high-dose naltrexone in patients with co-occurring cocaine and alcohol dependence

This is a randomized, double-blind, placebo-controlled clinical trial that evaluated the efficacy of a higher-than-typical daily dose of naltrexone (150 mg/day), taken for 12 weeks, in 164 patients (n = 116 men and n = 48 women) with co-occurring cocaine and alcohol dependence. Patients were stratified by gender and then randomly assigned to either naltrexone or placebo, and to either cognitive-behavioral therapy or a type of medical management. The two primary outcomes were cocaine use and alcohol use. Significant Gender x Medication interactions were found for cocaine use via urine drug screens (three way, with time) and self-reports (two way) for drug severity (two way) and alcohol use (two way). The type of psychosocial treatment did not affect outcomes. Thus, 150 mg/day naltrexone added to a psychosocial treatment resulted in reductions in cocaine and alcohol use and drug severity in men, compared to higher rates of cocaine and alcohol use and drug severity in women.

Mechanisms of acute cocaine toxicity

Patients with acute cocaine poisoning present with life-threatening symptoms involving several organ systems. While the effects of cocaine are myriad, they are the result of a limited number of cocaine-protein interactions, including monoamine transporters, neurotransmitter receptors and voltage-gated ion channels. These primary interactions trigger a cascade of events that ultimately produce the clinical effects. The purpose of this article is to review the primary interactions of cocaine and the effects that these interactions trigger. We also describe the progression of symptoms observed in cocaine poisoning as they relate to serum cocaine concentrations.

Markers of chronic alcohol use in hair: Comparison of ethyl glucuronide and cocaethylene in cocaine users

Two direct ethanol metabolites, namely ethyl glucuronide (EtG) and cocaethylene (CE), in the hair of cocaine (COC) users were compared in this study. Hair samples (n=68) were submitted to the determination of EtG (by liquid chromatography-electrospray-tandem mass spectrometry) and of COC and metabolites, including CE (by gas chromatography-mass spectrometry). Quantitative and qualitative results were compared. No quantitative correlation was found between EtG and CE, as well as between EtG and the cocaethylene concentration divided by the concentration of COC and its metabolites (benzoylecgonine and ecgonine methylester, as COC equivalents). Nevertheless, many factors are supposed to affect the amount of the two substances incorporated in the hair matrix, such as the subject's habits in ethanol and COC use, genetic variability in the metabolism of both substances, and the different chemical and physical properties of EtG and CE. When establishing a cut-off of 4 pg/mg for EtG and of 200 pg/mg for CE, 47 samples tested positive for EtG and 41 samples tested positive for CE; 12 samples out of the 47 EtG-positives tested negative for CE (25%), whereas 6 samples out of the 41 CE-positives tested negative for EtG (15%). According to these data, EtG appears to be a more sensitive and specific marker of non-moderate alcohol users than CE.

Concurrent use and order of use of cocaine and alcohol: behavioural differences between users of crack cocaine and cocaine powder

AIMS

The study investigates patterns of cocaine use and alcohol use when these substances were taken on their own, the order of administration of alcohol and of cocaine when the two substances were taken together, and changes in the doses of alcohol and of cocaine when the two substances were taken together. The study further investigates differences in the combined use of the two substances by users of cocaine powder and crack cocaine.

DESIGN

Entry criteria for the study were current (previous 30 days) use of both alcohol and cocaine. Study participants (n = 102) were recruited from clinical and non-clinical settings. Data were collected by face-to-face structured interviews.

FINDINGS

Different patterns of combined cocaine and alcohol use were reported by cocaine powder and crack cocaine users. Cocaine powder users tended to take increased doses of both cocaine and alcohol when these were used in combination. During high-dose crack using episodes, crack users tended to drink lower amounts of alcohol than usual. Cocaine powder users tended to use cocaine and alcohol concurrently. Crack users tended to use alcohol at the end of crack-using sessions.

CONCLUSIONS

The observed differences are not understood clearly but may be influenced by differential effects of route of administration upon absorption, bioavailability and the balance of euphoric/dysphoric effects. Research studies of the combined use of cocaine and alcohol should distinguish explicitly between the use of cocaine by different routes of administration, and this should be specified in the description of subject samples.

Frequency of recent cocaine and alcohol use affects drug craving and associated responses to stress and drug-related cues

RATIONALE

Stress is known to increase drug craving, associated physiological arousal and risk of relapse in drug dependent individuals. However, it is unclear whether these responses are altered by recent frequency of drug use. The current study examined whether frequency of cocaine and alcohol abuse alters drug craving and associated arousal with laboratory exposure to stress and to drug related cues.

METHODS

Fifty-four recently abstinent treatment-seeking cocaine abusers who were part of a study on stress and drug craving were categorized into high- and low-frequency users on the basis of their recent cocaine use. The high use cocaine group also consumed significantly more alcohol than the low use cocaine group. Participants were exposed to a brief 5-min guided imagery procedure that involved imagining a recent personal stressful situation, a personal drug-related situation and a neutral-relaxing situation, one imagery session on separate days presented in random order. Subjective (craving and anxiety), cardiovascular (heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP)) and biochemical (adrenocorticotropic hormone (ACTH), cortisol, prolactin) measures were assessed.

RESULTS

High-frequency abusers demonstrated a significantly greater drug craving, anxiety and associated cardiovascular and hypothalamic-pituitary-adrenal (HPA) response to both stress and drug-cue exposure as compared to low-frequency abusers.

CONCLUSIONS

Increased frequency of recent cocaine and alcohol use is associated with an enhanced stress and cue-induced drug craving and arousal response that appears to be similar to the effects of cocaine, and one that may increase the vulnerability to drug-seeking behavior and relapse in drug dependent individuals.

Development of Monoclonal Antibodies Directed Against Cocaine and Cocaethylene: Potential New Tools for Immunotherapy

Cocaine abuse is a major health problem, with the number of overdose-related incidents on a constant increase. Monoclonal antibodies against cocaine and its major toxic metabolite cocaethylene, have been developed for immunotherapeutical neutralization in vivo. A series of monoclonal antibodies with high affinity for cocaethylene and cocaine were obtained. Clones DASm244-4D8A4A4 (4D8) and DASm244-5B3C3C6 (5B3) were selected and fully characterized. The antibodies secreted exhibited 1.40 x 10(8) and 3.69 x 10(7) M(-1) affinity constants for [3H]-cocaine and cocaethylene, respectively. In addition to cocaine, they bound to cocaethylene and did not recognize non-toxic cocaine metabolites. They did not bind to blood cells, indicating that they may be potential tools for cocaine neutralization in vivo in cases of overdose.

Electrophysiologic and Hemodynamic Effects of Sodium Bicarbonate in a Canine Model of Severe Cocaine Intoxication

OBJECTIVE

Cocaine toxicity causes myocardial depression, malignant dysrhythmias, and sudden death, partially due to cocaine-related myocardial sodium channel blockade. Because of cocaine's ability to block cardiac sodium channels, sodium bicarbonate (NaHCO3) has been proposed as an antidote. The hypothesis of this study was that NaHCO3 would correct cocaine-induced conduction abnormalities and resultant hemodynamic compromise in an animal model simulating severe cocaine intoxication.

METHODS

DESIGN

Prospective, controlled, experimental study in which 15 anesthetized dogs were given three successive boluses of cocaine (7 mg/kg) and then randomized to receive NaHCO3, 2 mEq/kg (n = 8) or placebo (n =7).

MEASUREMENTS

Arterial, left ventricular, and pulmonary artery pressures; cardiac output (CO); electrocardiogram (ECG); blood gases; and serum concentrations of cocaine were measured at baseline, at fixed time intervals after each bolus of cocaine, and then after administration of NaHCO3 or placebo. Statistical significance was determined by analysis of variance (ANOVA) for repeated measures.

RESULTS

Seven dogs experienced significant arrhythmias, including VT, pulseless electrical activity, and third-degree atrioventricular block; 2 of these dogs expired prior to receiving NaHCO3 and were excluded. Immediately after administering NaHCO3, QRS duration decreased by 30% (p < 0.001), returning to baseline more quickly than in the control group. This effect was associated with a brief 30% decrease in MAP (p = NS). After NaHCO3, CO increased 78% and remained increased for 5 min (p < 0.007). One dog converted from complete heart block to sinus rhythm shortly after NaHCO3 administration.

CONCLUSIONS

NaHCO3 improved ECG changes secondary to cocaine toxicity and improved myocardial function.

Cardiovascular manifestations of substance abuse part 1: cocaine

Substance abuse with cocaine is associated with multiple cardiovascular conditions, including myocardial infarction, dissection, left ventricular hypertrophy, arrhythmias, sudden death, and cardiomyopathy. Cocaine has effects to potentiate the physiologic actions of catecholamines and has direct effects on voltage-dependent sodium ion channels related to local anesthetic properties. The effects of cocaine can be augmented with concomitant alcohol consumption. Acute myocardial ischemia caused by cocaine may be related to in situ thromboisis and/or coronary vasospasm. Treatment strategies for cocaine-induced myocardial infarction would include antiplatelet therapy, thrombolysis, and vasodilators (eg, nitrates, nifedipine). Beta-adrenergic blockers should not be used unless concomitant vasodilator therapy is given.

Cocaethylene's effects on coronary artery blood flow and cardiac function in a canine model

OBJECTIVES

Cocaethylene is a toxic metabolite of cocaine formed in the presence of ethanol. Though cocaine causes coronary vasoconstriction, cocaethylene's effects on coronaryflow are unknown. The aim of our study was to describe cocaethylene 's effects on coronary flow and cardiac function.

METHODS

Sixteen alpha-chloralose anesthetized dogs were monitored with Swan-Ganz, arterial and venous catheters, and an electrocardiogram. Dopplerflow probes were placed on the circumflex and left anterior descending coronary arteries. Dogs were allotted 15 mg/kg (n = 10) or 30mg/kg (n = 6) of cocaethylene given as a continuous intravenous infusion. Measurements were made at fixed time intervals during the 60-minute cocaethylene infusion and 2-hour observation period.

RESULTS

The cocaethylene concentrations were maximal at the end of the infusion and cocaethylene was rapidly metabolized to benzoylecognine. One low-dose animal died of ventricular fibrillation. Five high-dose dogs experienced ventricular arrhythmias or pulseless electrical activity (PEA), and three died. In the low-dose group, cocaethylene caused a 38% increase in mean arterial pressure relative to baseline, and increased systemic vascular resistance. In the high-dose group, at maximal cocaethylene concentrations, stroke volume decreased by 42% (p < 0.0002), and circumflex blood flow decreased by 30% (p = 0.03) relative to baseline, when arrhythmias occurred. The PR, QRS, and QTc intervals increased by 48, 209, and 29%, respectively (p < 0.001). As cocaethylene levels declined, circumflex blood flow increased by 77% (p = 0.05) and mean arterial pressure increased 49% (p < 0.01), also relative to baseline.

CONCLUSIONS

Cocaethylene caused hypertension and increased systemic vascular resistance. At high concentrations, it decreased myocardial function, slowed cardiac conduction, and was arrhythmogenic. The cocaethylene's toxicity does not appear to be mediated by effects on coronary blood flow.

Effects of chronic methamphetamine exposure on heart function in uninfected and retrovirus-infected mice

Methamphetamine (MA) increases catecholamine levels, which have detrimental effects on heart function through vasoconstriction, myocardial hypertrophy, and fibrosis. Murine retrovirus infection induces dilated cardiomyopathy (DCM). The present study investigated the cardiovascular effects of chronic MA treatment on uninfected and retrovirus-infected mice. C57BL/6 mice were studied after 12 weeks treatment. The four study groups were (group I) uninfected, MA placebo; (group II) infected, MA placebo; (group III) uninfected, MA treatment; and (group IV) infected and MA treatment. MA injections were given i.p. once a day for 5 days/week with a increasing dose from 15 mg/kg to 40 mg/kg. Left ventricular mechanics were measured in situ a using Millar conductance catheter system for pressure-volume loop analysis. Cardiac pathology was determined with histological analysis. In the uninfected mice, the load independent contractile parameters, pre-load recruitable stroke work (PRSW) and dP/dt(max) vs. Ved, significantly decreased by 32% and 35% in MA treated mice when compared to the saline injected mice. In retrovirus-infected mice, although there were no significant difference in Ees, PRSW, and dP/dt(max) vs. Ved due to MA treatment, they were increased 45%, 15% and 42% respectively when compared to saline treated mice. No further lowered heart function during murine AIDS may be due to the counteraction of the retroviral DCM and the MA induced myocardial fibrosis and hypertrophy (thickening of the ventricular walls). This is supported by increases in the End-diastolic volume (Ved, 38%) and End-systolic volume (Ves, 84%) in the retrovirus-infected saline injected mice, the decreases of 33% and 17% in the uninfected MA-treated mice, but no significant changes in the retrovirus-infected MA treated mice when compared to uninfected saline injected mice. These data suggest that MA induced myocardial cellular changes compensate for retrovirus induced DCM.

Acute aortic dissection related to crack cocaine

BACKGROUND

Although single case reports have described acute aortic dissection in relation to cocaine use, this condition is not widely recognized, and the features of cocaine-related aortic dissection have not been defined.

METHODS AND RESULTS

We reviewed all available hospital charts from 1981 to 2001 with the ICD-9 diagnosis of aortic dissection. Among the 38 cases of acute aortic dissection, 14 (37%) were related to cocaine use. Crack cocaine was smoked in 13 cases and powder cocaine was snorted in 1 case. The mean interval between cocaine use and the onset of symptoms was 12 hours (range, 0 to 24). Patients with cocaine-related dissection were much younger and more likely to undergo surgery compared with patients with aortic dissection without cocaine use. Most in the cocaine group were black, with a history of untreated hypertension. However, the two groups did not differ in other respects, including dissection type.

CONCLUSIONS

In an inner city population, acute aortic dissection in the setting of crack cocaine use is common, presumably as a consequence of abrupt, transient, severe hypertension and catecholamine release. This diagnosis should be considered in cocaine users with severe chest pain.