Cocaine: pathophysiology and clinical toxicology

Folklore, Animal Self-Medication, and Phytotherapy-Something Old, Something New, Something Borrowed, Some Things True

The use of medicines was long considered by Western schools of thought to be a a domain unique to humans; however, folklore/Traditional Ecological Knowledge (TEK) from around the world suggests that animals have also long provided inspiration for the discovery of some medicinal plants used to treat humans and their livestock. Searching for medicinal knowledge from animals depends on the recognition of their ability to select and effectively use medicinal plants to prevent or actively ameliorate disease and other homeostatic imbalances. The interdisciplinary field of animal self-medication is providing scientific evidence for this ability in species across the animal kingdom and lends support to animal-origin medicinal plant folklore and recent ethnomedicinal information. Here, 14 case studies of purported animal-inspired plant medicines used by cultures around the world are presented together with ethnomedicinal and pharmacological evidence. Based on this evidence, the diversity and potential mode of self-medicative behaviors are considered. Over 20 animal species, including llama, sloth and jaguar in South America, reindeer and yak in Eurasia, langur and macaque in Asia, and chimpanzee, wild boar, porcupine and elephant in Africa, are linked to these case studies, representing a variety of potential preventative or therapeutic self-medicative behaviors. These examples provide an important perspective on what is likely to have been a much wider practice in the development of human traditional medicine. A role for animal self-medication research in the rejuvenation of old therapies and possible new discoveries of phytotherapies for human and livestock health is encouraged.

"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.

Sustained splenic contraction after daily cocaine administration in rats

The purpose of this study is to examine the effect of repeated cocaine administration on the whole body of rats. Rats (male, 6 weeks old, Sprague Dawley) were injected intraperitoneally with cocaine (50 mg/kg) once a day for 1, 3 or 7 days, and major organs (heart, liver, lung, brain, kidney, spleen) were excised from the sacrificed animals. During autopsy, we found a reduction in spleen size, but not other organs, in cocaine-administered rats as compared to control rats. This reduction became to be noticed at 3 day and easily perceived at 7 day. No marked changes were observed in other organs examined. H&E and EMG staining showed a tendency for a decrease in the number of red blood cells (RBCs) as well as an increase in collagen fibers in the spleens of rats treated repeatedly with cocaine. Transcriptome analysis indicated that repeated cocaine administration depletes RBCs from the spleen. Immunoblot analysis showed that cocaine increases the phosphorylation of myosin light chain (MYL) as well as the levels of transgelin, both of which are involved in the contraction of myofibrils. Collectively, these results show that repeated cocaine administration results in sustained contraction of the spleen, which leads to the release of RBCs from the spleen into circulation.

Cocaine Use in Adolescents and Young Adults

Cocaine use by adolescents and young adults continues to be a significant public health issue and the cause of medical and psychological morbidity and mortality. Although use rates are lower than those seen with alcohol, tobacco, and other illicit substances such as marijuana, cocaine is highly addictive and presents significant acute and long-term medical and psychological effects. This article reviews the epidemiology of cocaine use among adolescents and young adults, discusses the pharmacology and neurobiology of cocaine use and dependence, provides information regarding acute intoxication and systemic effects seen with more chronic use, and describes current assessment and treatment approaches.

Intravenous Cocaine Results in an Acute Decrease in Levels of Biomarkers of Vascular Inflammation in Humans

Cocaine use causes significant cardiovascular morbidity from its hemodynamic effects. It is less clear whether cocaine promotes atherosclerosis. Vascular inflammation is one of the earliest steps in the pathophysiology of atherosclerosis. We hypothesized that cocaine results in an increase in inflammatory markers. Study objective was to measure the acute effects of intravenous cocaine on biomarkers of vascular inflammation. Eleven chronic cocaine users were enrolled. After a drug-free period, they received intravenous cocaine at 0.36 mg/kg dose in an in-hospital controlled environment. Serum levels of soluble CD40 ligand, monocyte chemoattractant protein-1, interleukin 6, and soluble intercellular adhesion molecule-1 were measured at baseline, 6 h, 24 h, and 6 days after cocaine challenge and at baseline for controls. After cocaine challenge, sCD40 ligand levels decreased in subjects and were significantly lower at 24 h. MCP-1 levels decreased and were significantly lower at the 6-day time point. No significant changes in IL-6 or sICAM-1 level were found. In conclusion, intravenous cocaine did not result in an increase in levels of inflammatory markers. Levels of MCP-1 and sCD40L decreased significantly. This unexpected finding suggests that chronic effects of cocaine on inflammation may be different from acute effects or that higher dosing may have differential effects as compared to lower dose used here.

Coronary sinus flow is reduced in methamphetamine abusers: a transthoracic echocardiographic study

To compare the coronary sinus flow among healthy participants, methamphetamine abusers without chest pain and those with chest pain. One hundred and eight methamphetamine abusers: 53 ones without chest pain, 55 ones with chest pain, free of ascertained coronary artery disease, were enrolled in this study. A control group of 50 age-matched male healthy participants was studied for comparison. Standard 2D, flow and tissue Doppler echo with measurements of cardiac morphologic and functional indicators, coronary sinus flow, and inferior vena cava (IVC) ultrasound with measurements of the IVC dimensions and their collapsibility index were performed, respectively. Compared to healthy participants, methamphetamine abusers had higher blood pressure, greater left ventricular mass index and more impaired diastolic function, with preserved cardiac sizes, systolic function and right atrial pressure. Methamphetamine abusers with chest pain had faster heart rate than those without chest pain and healthy participants. Coronary sinus flow was significantly less in methamphetamine abusers than in healthy participants (P < 0.05), and was extremely lower in those with chest pain than in healthy participants (about one-fourth) (P < 0.01). The area under the curve (AUC) of coronary sinus flow was 0.913 (0.864-0.962), and the cutoff value with 221.65 mL/min had sensitivity of 83.4%, specificity of 87.2% and accuracy of 85.2% for differentiating methamphetamine abusers from healthy participants. While the AUC of coronary sinus flow was 0.996 (0.989-1.003), and the cutoff value with 172.59 mL/min had sensitivity of 100%, specificity of 93.3% and accuracy of 96.5% for predicting methamphetamine abusers with chest pain. Coronary sinus flow is significant reduced in methamphetamine abusers, which is maybe a good indicator for indentifying methamphetamine abusers from normal population, and for predicting methamphetamine abusers with chest pain.

Cocaethylene, the in vivo product of cocaine and ethanol, is a narcotic more potent than its precursors

The molecular conformation and supramolecular architecture of cocaethylene [systematic name: ethyl (1R,2R,3S,5S)-3-benzoyloxy-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate], C₁₈H₂₃NO₄, have been determined for the first time. Cocaethylene is a narcotic produced in vivo when cocaine and ethanol are administered concomitantly. The intra- and intermolecular features of cocaethylene and its less potent narcotic precursor cocaine are very similar. The only molecular difference is in the conformation of the methyl group of the ethoxycarbonyl group. Similar to cocaine, the carboxylate atoms and the α-C atom are coplanar in cocaethylene, but the methyl C atom of the ethyl group is bent by ca 90° away from this plane in the narcotic reported here. The main supramolecular motif is a one-dimensional chain stabilized by weak C-H...O contacts.

Substance Use, Intoxication, and Withdrawal in the Critical Care Setting

Substance use is common among individuals admitted to the critical care setting and may complicate treatment of underlying disorders. Management issues include the effects of intoxication as well as the risk posed by substance-withdrawal syndromes in patients being treated for critical illness. This article reviews the epidemiology of substance use in this population and the identification and treatment of common intoxication and withdrawal syndromes. The authors stress the importance of long-term planning as part of the overall treatment protocol beyond the acute presentation.

Biomarkers for Success: Using Neuroimaging to Predict Relapse and Develop Brain Stimulation Treatments for Cocaine-Dependent Individuals

Cocaine dependence is one of the most difficult substance use disorders to treat. While the powerful effects of cocaine use on behavior were documented in the 19th century, it was not until the late 20th century that we realized cocaine use was affecting brain tissue and function. Following a brief introduction (Section 1), this chapter will summarize our current knowledge regarding alterations in neural circuit function typically observed in chronic cocaine users (Section 2) and highlight an emerging body of literature which suggests that pretreatment limbic circuit activity may be a reliable predictor of clinical outcomes among individuals seeking treatment for cocaine (Section 3). Finally, as the field of addiction research strives to translate this neuroimaging data into something clinically meaningful, we will highlight several new brain stimulation approaches which utilize functional brain imaging data to design noninvasive brain stimulation interventions for individuals seeking treatment for substance dependence disorders (Section 4).

Stimulant Use Disorders

Compared with other illicit substances, stimulants are not commonly used by adolescents; however, they represent a serious concern regarding substance use among youths. This article uses methamphetamine as a model for stimulant use in adolescents; cocaine and prescription stimulants are also mentioned. Methamphetamine use among adolescents and young adults is a serious health concern with potentially long-term physical, cognitive, and psychiatric consequences. Brain development and the effects of misusing stimulants align such that usage in adolescents can more dangerous than during adulthood. It seems helpful to keep in mind the differences between adolescents and young adults when implementing interventions.

Acute Cocaine Toxicity: Pharmacology and Clinical Presentations in Adult and Pediatric Populations

Cocaine remains the most prevalent drug responsible for emergency department (ED) visits. A majority of acute cocaine toxicity cases involve young, habitual, adult cocaine users and often present with a range of cardiac, neurologic, gastrointestinal (GI) or renal symptoms. In addition, atypical populations (neonates, infants, toddlers, young children and adolescents) are presenting in EDs with varying symptoms that are unknowingly associated with cocaine exposure. Unfortunately, juvenile presentations are generally anecdotal in nature, and while enlightening, are difficult to quantify epidemiologically. Outlining the types of symptom presentation in these young populations may assist healthcare providers in expediting proper treatment for such demographic groups. Therefore, this review examines the current knowledge regarding cocaine's pharmacologic activity as it relates to its potential toxicity, and outlines the clinical manifestations of cocaine exposure and toxicity in adult and pediatric populations. We conclude from the available clinical reports that there must be a higher index of suspicion in the pediatric population to identify exposed infants and children. Improved recognition and identification in both typical and atypical populations will result in better characterization of acute cocaine toxicity.

Assessing cocaine abuse using LC-MS/MS measurements in biological specimens

Cocaine use is still a problem in today's world, and this has several implications on human activities. Indeed, important problems related to cocaine derive from its use in situations where concentration and focus skills are necessary, namely while driving and/or working. The need of analytical methods for drug analysis in specimens of biological origin for proper documentation of human exposure is increasing. While GC-MS-based procedures represented the state-of-the-art of analytical techniques a few years ago, there is a growing trend for their replacement by LC-MS/MS, which can be justified by the increased sensitivity presented by these new technologies. This paper will review recently published papers on the use of LC-MS/MS-based procedures for cocaine measurement in biological specimens.

Coca: The History and Medical Significance of an Ancient Andean Tradition

Coca leaf products are an integral part of the lives of the Andean peoples from both a cultural and traditional medicine perspective. Coca is also the whole plant from which cocaine is derived. Coca products are thought to be a panacea for health troubles in regions of South America. This review will examine the toxicology of whole coca and will also look at medicinal applications of this plant, past, present, and future.

Crack abuse during pregnancy: maternal, fetal and neonatal complication

OBJECTIVE

The aim of this study was to assess the effects of crack on pregnancy outcomes.

METHODS

We studied 88 crack user pregnant women in this study. These women were matched to a drug-free group (n = 90) chosen from the population of the same hospital. Maternal outcomes including preeclampsia, placenta abruption, gestational diabetes and preterm labor, and neonatal complication including low birth weight and low Apgar score in 5 min were compared in crack using and drug-free groups. Data were analyzed by SPSS software. Chi-square test and Student's t-test and Relative Risks (RRs) were used in this study.

RESULTS

The results of our study showed that crack abuse during pregnancy was associated with higher rate of preeclampsia p = 0.003 (RR, 1.731; 95% CI, 1.777-2.545), placental abruption p = 0.001 (RR, 2.439; 95% CI, 1.369-4.343), preterm labor p < 0.000 (RR, 3.249; 95% CI, 2.053-5.141) and low birth weight p < 0.000 (RR, 2.179; 95% CI, 1.462-3.247).

CONCLUSIONS

Crack abuse had significant influence on pregnancy outcomes. Crack appears to influence the prevalence of low birth weight, preterm labor, preeclampsia and placental abruption.

Xylazine as a drug of abuse and its effects on the generation of reactive species and DNA damage on human umbilical vein endothelial cells

Human xylazine (XYL) abuse among addicts has received great interest due to its potential toxic effects upon addicts and the need to understand the mechanism of action associated with the potential health effects. XYL is an alpha-2 agonist restricted to veterinarian applications, without human medical applications. Our previous work demonstrated that XYL and its combination with cocaine (COC) and/or 6-monoacetylmorphine (6-MAM) induce cell death through an apoptotic mechanism. The aim of this study was to determine the effect of xylazine on the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as well as DNA damage on endothelial cell. Human umbilical vein endothelial cells (HUVEC) were treated with XYL (60 μM), COC (160 μM), 6-MAM (160 μM), camptothecin (positive control, 50 μM), XYL/COC (50 μM), XYL/6-MAM (50 μM), and XYL/COC/6-MAM (40 μM) for a period of 24 hours. Generation of intracellular ROS, RNS, and DNA fragmentation were analyzed using a fluorometric assay. Results reveal that XYL and 6-MAM increase levels of ROS; no induction of RNS production was observed. The combination of these drugs shows significant increase in DNA fragmentation in G2/M phase, while XYL, COC, and 6-MAM, without combination, present higher DNA fragmentation in G0/G1 phase. These findings support that these drugs and their combination alter important biochemical events aligned with an apoptotic mechanism of action in HUVEC.

Toxic effects of xylazine on endothelial cells in combination with cocaine and 6-monoacetylmorphine

The use of xylazine as a drug of abuse has emerged worldwide in the last 7 years, including Puerto Rico. Clinical findings reported that xylazine users present greater physiological deterioration, than heroin users. The aim of this study was to assess the xylazine toxicity on endothelial cells, as this is one of the first tissues impact upon administration. Human umbilical vein endothelial cells in culture were treated with xylazine, cocaine, 6-monoacetylmorphine (heroin metabolite) and its combinations, at concentrations of 0.10-400 μM, for periods of 24, 48 and 72 h. IC50 were calculated and the Annexin V assay implemented to determine the cell death mechanism. Results indicated IC50 values at 24h as follow: xylazine 62 μM, cocaine 210 μM, 6-monoacetylmorphine 300 μM. When these drugs were combined the IC50 value was 57 μM. Annexin V results indicated cell death by an apoptosis mechanism in cells treated with xylazine or in combination. Results demonstrated that xylazine use inhibits the endothelial cell proliferation, at lower concentrations than cocaine and 6-monoacetylmorphine. These findings contribute to the understanding of the toxicity mechanisms induced by xylazine on endothelial cells.

Clinical aspects and care production in a Brazilian psychosocial care center of alcohol and other drugs (CAPS AD)

The study aimed to analyze the clinical aspects of the treatment of crack cocaine and excessive alcohol users who were seen in a Psychosocial Care Center of Alcohol and Other Drugs (CAPS AD) in Sobral, Ceará, during the years 2010 and 2011. This is an exploratory descriptive and documentary study, with a retrospective quantitative approach. The sample was composed of 567 medical records of drug users, from which 291 were crack cocaine users, and 276 were alcohol users. For data collection, a form was developed based on the Care Script Service, the data from which was then used to populate a database in an EPI INFO 7, a statistics software system. In both groups of users, males were predominant (85%, n = 482), and were between the ages of 20 and 29 years for crack users (50.9%, n = 148), and between 30 and 39 years for alcohol users (31.9%, n = 88). There were significant differences between crack cocaine users and alcohol users in liver disorders (p < 0.01) and withdrawal syndrome (p < 0.05), however, there were similar signs and symptoms between users. Crack users hospitalized less frequently (OR 0.33 [95% CI 0.23 to 0.47 p < 0.01]). Suicidal ideation and suicide attempts were similar in both crack cocaine and alcohol users. Thus, this research will lead to new proposals for health care professionals in order to enhance and improve the care provided to service customers in CAPS AD.

Neuropathology of substance use disorders

Addictions to licit and illicit drugs are chronic relapsing brain disorders that affect circuits that regulate reward, motivation, memory, and decision-making. Drug-induced pathological changes in these brain regions are associated with characteristic enduring behaviors that continue despite adverse biopsychosocial consequences. Repeated exposure to these substances leads to egocentric behaviors that focus on obtaining the drug by any means and on taking the drug under adverse psychosocial and medical conditions. Addiction also includes craving for the substances and, in some cases, involvement in risky behaviors that can cause death. These patterns of behaviors are associated with specific cognitive disturbances and neuroimaging evidence for brain dysfunctions in a diverse population of drug addicts. Postmortem studies have also revealed significant biochemical and/or structural abnormalities in some addicted individuals. The present review provides a summary of the evidence that has accumulated over the past few years to implicate brain dysfunctions in the varied manifestations of drug addiction. We thus review data on cerebrovascular alterations, brain structural abnormalities, and postmortem studies of patients who abuse cannabis, cocaine, amphetamines, heroin, and "bath salts". We also discuss potential molecular, biochemical, and cellular bases for the varied clinical presentations of these patients. Elucidation of the biological bases of addiction will help to develop better therapeutic approaches to these patient populations.

Etiology and therapeutic approach to elevated lactate levels

Lactate levels are commonly evaluated in acutely ill patients. Although most often used in the context of evaluating shock, lactate levels can be elevated for many reasons. While tissue hypoperfusion may be the most common cause of elevation, many other etiologies or contributing factors exist. Clinicians need to be aware of the many potential causes of lactate level elevation as the clinical and prognostic importance of an elevated lactate level varies widely by disease state. Moreover, specific therapy may need to be tailored to the underlying cause of elevation. The present review is based on a comprehensive PubMed search between the dates of January 1, 1960, to April 30, 2013, using the search term lactate or lactic acidosis combined with known associations, such as shock, sepsis, cardiac arrest, trauma, seizure, ischemia, diabetic ketoacidosis, thiamine, malignancy, liver, toxins, overdose, and medication. We provide an overview of the pathogenesis of lactate level elevation followed by an in-depth look at the varied etiologies, including medication-related causes. The strengths and weaknesses of lactate as a diagnostic/prognostic tool and its potential use as a clinical end point of resuscitation are discussed. The review ends with some general recommendations on the management of patients with elevated lactate levels.

Atypical gastric ulcer in an elderly cocaine user

Cocaine or Benzoylmethylecgonine is an alkaloid extracted from the leaves of the Erythroxylon plant, which can cause gastrointestinal ischemia from severe arterial vasoconstriction via stimulation of alpha-adrenergic receptors in the gastric and mesenteric arteries. We report this case of a 65-year-old man who presented with a single massive ulcer at the incisura of the stomach as a result of cocaine use. The size and location of this ulcer were atypical and illustrate the potential for serious gastrointestinal manifestations from cocaine use.

Dacryocystitis secondary to intranasal cocaine abuse: a case report and literature review

PURPOSE

To report a case of dacryocystitis secondary to intranasal cocaine abuse and to review the literature on the effects of cocaine on sinus, nasal and lacrimal structures.

METHODS

Case report and literature review.

RESULTS

A 33-year-old male presented with unilateral epiphora and discharge, and clinical examination was consistent with dacryocystitis. He had a 2-year history of intranasal cocaine use. Computed tomography revealed extensive bilateral intranasal and sinus destruction, consistent with cocaine abuse. He was treated with antibiotics followed by dacryocystorhinostomy with silicone intubation. He had 2 recurrences of dacryocystitis and underwent one additional lacrimal surgery.

CONCLUSIONS

Cocaine abuse and its accompanying intranasal and sinus destruction should be considered when determining the etiology of nasolacrimal obstruction and dacryocystitis. A medical and social history with specific questions about drug abuse may be useful. Computed tomography is helpful in delineating damage to the sinuses, nose and lacrimal system. Management with antibiotics and dacryocystorhinostomy surgery may result in resolution of symptoms.

Cell permeable cocaine esterases constructed by chemical conjugation and genetic recombination

Cocaine esterase (CocE) is the most efficient cocaine-metabolizing enzyme tested in vivo to date, displaying a rapid clearance of cocaine and a robust protection against cocaine's toxicity. Two potential obstacles to the clinical application of CocE, however, lie in its proteolytic degradation and induced immune response. To minimize these potential obstacles, we attempted nondisruptive cell encapsulation by creating a cell permeable form of CocE, which was achieved by covalently linking a thermally stable CocE mutant (dmCocE) with cell penetrating peptides (CPPs). Two types of CPPs, Tat and the low molecular weight protamine (LMWP), were used in this study. Two types of disulfide-bridged chemical conjugates, Tat-S-S-dmCocE and LMWP-S-S-dmCocE, were synthesized and then purified by heparin affinity chromatography. In addition, four recombinant CPP-dmCocE fusion proteins, Tat-N-dmCocE, LMWP-N-dmCocE, dmCocE-C-Tat, and dmCocE-C-LMWP, were constructed, expressed in Escherichia coli, and purified as soluble proteins. Among these six CPP-dmCocE variants, LMWP-S-S-dmCocE showed the highest cocaine-hydrolyzing activity, and dmCocE-C-Tat had the highest production yield. To evaluate their cellular uptake behavior, a covalently linked fluorophore (FITC) was utilized to visualize the cellular uptake of all six CPP-dmCocE variants in living HeLa cells. All the six variants exhibited cellular uptake, but their intracellular distribution phenotypes differed. While the chemical conjugates showed primarily cytoplasmic distribution, which was likely due to the reduction of the disulfide linkage between CPP and dmCocE, all the other four recombinant fusion proteins displayed both nuclear and cytoplasmic localization, with dmCocE-C-CPP exhibiting higher cytoplasmic distribution during cellular uptake. Based on a balanced consideration of essentials for clinical application, including parameters such as high cocaine-hydrolyzing efficiency, large production yield, major cytoplasmic distribution, etc., the dmCocE-C-Tat fusion protein seems to be the best candidate from this investigation. Further in vivo studies of the cell-encapsulated dmCocE-C-Tat in hydrolyzing cocaine and alleviating immunogenicity and proteolytic degradation in established, clinically relevant mouse models are currently underway in our laboratories. Findings from this research are not only useful for developing other new CPP-CocE constructs but also valuable for establishing a nondisruptive cell-encapsulation technology for other protein therapeutics that are known to be immunogenic for direct clinical application.

Bioanalytical methods for the determination of cocaine and metabolites in human biological samples

Determination of cocaine and its metabolites in biological specimens is of great importance, not only in clinical and forensic toxicology, but also in workplace drug testing. These compounds are normally screened for using sensitive immunological methods. However, screening methods are unspecific and, therefore, the posterior confirmation of presumably positive samples by a specific technique is mandatory. Although GC-MS-based techniques are still the most commonly used for confirmation purposes of cocaine and its metabolites in biological specimens, the advent of LC-MS and LC-MS/MS has enabled the detection of even lower amounts of these drugs, which assumes particular importance when sample volume available is small, as frequently occurs with oral fluid. This paper will review recently-published papers that describe procedures for detection of cocaine and metabolites, not only in the most commonly used specimens, such as blood and urine, but also in other 'alternative' matrices (e.g., oral fluid and hair) with a special focus on sample preparation and chromatographic analysis.

Lesson of the month (1). Ictal asystole due to unsuspected cocaine abuse

This lesson describes a patient who had a cardiac arrest during an episode of status epilepticus provoked by a first fit. This is an exceptional sequence of events and should lead to investigation for an underlying cause. Unsuspected cocaine abuse is common and may provoke prolonged status epilepticus, particularly if there is a low seizure threshold. A toxic screen should be undertaken in all patients presenting with unexplained status epilepticus even if abuse of illicit substances is denied.

[Anesthesia in drug addiction]

The growing social problem of drug abuse has increased the likelihood that anesthesiologists will find acute or chronic drug users among patients requiring anesthesia for elective or emergency surgery. We must therefore be aware of the effects drugs have on the organism and their possible pharmacokinetic and pharmacodynamic interactions with anesthetic agents in order to prevent complications during surgery and postoperative recovery. Such knowledge is required for the management of abstinence syndrome or overdose, which pose the greatest potential dangers for the hospitalized drug addict.

Stimulant abuse: pharmacology, cocaine, methamphetamine, treatment, attempts at pharmacotherapy

The high prevalence of stimulant abuse and its harmful consequences make the screening, diagnosis, and referral for treatment of persons with stimulant abuse a top concern for primary care providers. Having a working knowledge of use patterns, clinical symptomatology, end-organ effects, and advances in treatment of stimulant abuse is essential. Although cocaine and amphetamine have different use patterns, duration of action, and so forth, the consequences of use are remarkably similar. Primary care is at the forefront of screening, brief risk reduction interventions, and diagnosis of medical sequelae, with referral to addiction specialist treatment when necessary.

The Health Effect of Psychostimulants: A Literature Review

Prevalence of psychostimulant use is high, and raising in several countries. Nicotine is the legal stimulant causing the most important public health impact. Cocaine ranks among the most used illicit substances after cannabis. Stimulant medications are frequently misused. Psychostimulants can lead to addiction, have physical, psychological and social health consequences and can induce a great disease burden. The aim of the present article is to provide a literature review on the health effects of stimulants as potential drugs of abuse. It will cover essentially cocaine, amphetamines and its derivatives (including methamphetamines and 3-4-methylenedioxymethamphetamine, ecstasy), nicotine, caffeine and khat, and touch upon the issues of prescribed substances (anti-depressants, weight control medications, attention-deficit hyperactivity disorder medications, hypersomniac disorder). Their pharmacology, addictive potential, health consequences and treatment will be discussed. We used Medline for the literature review from 1990 to the date of this review, and mention the findings of human and animal studies (the latter only if they are of clinical relevance).

Influence of verbal recall of a recent stress experience on anxiety and desire for cocaine in non-treatment seeking, cocaine-addicted volunteers

It has long been postulated that stress increases the risk of drug abuse and relapse. The principal goal of this project was to evaluate the effects of verbal recall of a recent stress experience (specifically meaningful to each individual) on physiological and subjective measures in cocaine-addicted participants. Subjects described a recent stressful non-drug-related experience and a neutral non-stressful experience, and then completed mood and drug effect questionnaires, while heart rate and blood pressure were recorded. Participants (N = 25) were predominantly African American and male. As a group, participants used cocaine for more than 15 years and approximately 18 of the last 30 days, and a majority reported use of nicotine and/or alcohol. All participants were evaluated during a time in which they tested positive for cocaine metabolite. On a scale of 1-10, participants reported their verbal recall of a recent stress event as highly stressful and their verbal recall of a recent neutral event as non-stressful (p < 0.0001). The self-reported vividness of this recall was high (>8 out of 10) for both the stress and neutral events. Heart rate and systolic and diastolic blood pressure did not differ after verbal recall of either stress or neutral events. Similarly, self-reported subjective effects (including ratings of anxiety and craving for cocaine) did not differ after verbal recall of either stress or neutral events. In summary, despite the fact that participants recounted highly stressful and vivid memories, this experience did not elicit significant changes in cardiovascular or subjective effects. These data suggest that simply recalling a stressful event may not be a sufficient enough stimulus to contribute to craving or relapse in cocaine-addicted individuals.

Signal-averaged electrocardiogram in physically healthy, recently abstinent chronic cocaine users

OBJECTIVES

: Cocaine use is associated with cardiac arrhythmias. Markers of ventricular late potentials, which may be a precursor to malignant ventricular arrhythmias, can be detected by signal-averaged electrocardiography (SA-ECG) but not by standard ECG.

METHODS

: We evaluated SA-ECG parameters in 60 medically screened, physically healthy, recently abstinent cocaine users (53 males, mean [SD] age, 34.0 [4.6] years; 10.1 [6.0] years of use) and 54 nondrug-using controls (21 males, mean [SD] age 28.4 [7.8] years). SA-ECGs were done periodically for ≤12 weeks of monitored abstinence in 25 cocaine users. We analyzed 3 SA-ECG parameters considered markers of ventricular late potentials: duration of filtered QRS complex, duration of low-amplitude potentials during terminal 40 ms of QRS complex (LAS40), and root mean square voltage during terminal 40 ms of QRS complex (RMS40).

RESULTS

: Cocaine users differed significantly from controls in filtered QRS complex (118.5 [11.2] ms versus 111.9 [11.4] ms; P = 0.03) but not in LAS40 (28.9 [8.2] ms versus 30.8 [8.3] ms; P = 0.40) or RMS40 (40.0 [19.8] μV versus 30.2 [20.1] μV; P = 0.06) values. The proportion of subjects with abnormal SA-ECG parameters did not differ significantly between male cocaine users and male controls. There were no significant changes over time in either the mean values or proportion of subjects with abnormal values for any SA-ECG parameter. There were significant gender differences among controls but not among cocaine users.

CONCLUSION

: These findings suggest that chronic cocaine use is not associated with a higher prevalence of abnormal SA-ECG parameters in physically healthy users.

Cocaine: history, social implications, and toxicity: a review

The amount of positive cocaine results in an urban emergency department are staggering. The ages of use are becoming more common in older age groups. Most of these patients have underlying medical conditions, including end-stage renal disease (on hemodialysis) and heart and lung disease. Most of their visits to the emergency department are for cocaine exacerbation of underlying chronic condition, adding exponentially to health care dollars. This article describes the history and pharmacology of illicit cocaine use.

Molecular analysis of cocaine-induced endothelial dysfunction: role of endothelin-1 and nitric oxide

Cocaine remains the most frequently used illicit substance. Although cocaine-induced atherosclerosis is well documented, its mechanism of action on human vascular endothelial cells has not been determined. Nitric oxide (NO) and endothelin-1 (ET-1) are involved in endothelial cell activation and leukocyte recruitment. The present study monitored the effects of cocaine on NO and ET-1 production in human aortic endothelial cells (HAECs) and the effects of sodium nitroprusside (SNP) and BQ-123 on leukocyte adhesion to HAECs. Acute exposure to cocaine (1 and 3 muM) significantly increased ET-1 production (2-fold) and ET-1 receptor type-A (ET(A)R) protein expression, within 6-12 h. Cocaine exposure for a longer duration (24-72 h) showed a temporal decrease in both NO production and endothelial NO-synthase (eNOS) expression. The cocaine-mediated suppression of NO was ameliorated by co-treatment of cells with the ET(A)R blocker, BQ-123 (5 muM). Furthermore, both short-term (24 h) and long-term (72 h) exposure to cocaine increased endothelial adhesion of monocytes (U937 cells) by 20% and 40%, respectively, which were also suppressed by BQ-123 and SNP co-treatment. These data suggest that a concomitant increase in both ET-1 and ET(A)R expression in cocaine exposed HAECs may enhance signaling via the ET(A)R which decreases eNOS expression and NO production, and ultimately results in endothelial activation and leukocyte adhesion. Our findings implicate a molecular mechanism of action of cocaine and a therapeutic effect of ET(A)R-specific inhibitor in suppressing the cocaine-induced endothelial dysfunction.

Cardiovascular complications of cocaine: imaging findings

Cocaine is the second most commonly abused illicit drug in the US and the most common one involved in emergency department visits, the majority of which are related to the cardiovascular system. Cardiovascular complications related with cocaine abuse include myocardial ischemia and infarction, myocarditis, hypertrophic cardiomyopathy, dilated cardiomyopathy, aortic dissection, thrombosis, stroke and cerebral hemorrhage, and different forms of visceral ischemia, among others. In an era where cocaine use has reached epidemic proportions, it is necessary for the radiologist to understand the pathophysiology, clinical presentation, and imaging characteristics of its cardiovascular complications.

Outcomes of cocaine-induced gastric perforations repaired with an omental patch

Crack cocaine has been associated with acute gastric perforation. The appropriate surgical treatment and long-term outcomes remain unclear. A retrospective chart review of all gastroduodenal perforations associated with crack cocaine use was performed. Data abstracted included details of short- and long-term outcomes. Kaplan-Meier methods were used to evaluate surgical outcomes. Over the 14-year period ending December 2005, 16 cases of crack-induced gastric perforations were identified. Most (75%) were treated with an omental patch. The other patients underwent a formal antiulcer operation, including one vagotomy and pyloroplasty (V&P), one vagotomy and antrectomy, one subtotal gastrectomy, and one ulcer excision and V&P. All patients after antiulcer procedures were followed for a median of 63 months (range 27-120) with no recurrences. Follow-up data were available in 75% of the omental patch patients. Recurrence of disease was observed in 56% of these omental patch patients at a median of 20 months (range 11-39). Those without recurrence were followed for a median of 67 months (range 12-96). The recurrence rate was borderline lower in the antiulcer group (P = 0.072). Omental patch closure results in a recurrence rate over 50% compared with no recurrence for formal antiulcer procedures.

Cocaine and thrombosis: a narrative systematic review of clinical and in-vivo studies

Purpose

To systematically review the literature pertaining to the link between cocaine and either arterial or venous thrombosis.

Procedures

Narrative systematic review of Medline, CINAHL, Embase, Psycinfo and Cochrane databases supplemented by hand trawling of relevant journals and reference lists up to April 2007. In-vivo studies and those with clinical endpoints were included in the review.

Results

A total of 2458 abstracts led to 186 full-text papers being retrieved. 15 met the criteria for inclusion in the review. The weight of evidence would support cocaine as a pro-thrombotic agent. There is evidence of it activating thrombotic pathways. The effect of cocaine upon clinical endpoints has not been quantified though there is evidence of an association between cocaine and myocardial infarction particularly amongst young adults. Cocaine may also be a causal agent in cerebrovascular accident though studies lacked sufficient power to determine a statistically significant effect. There is a gap in the evidence pertaining to the issue of cocaine and venous thrombosis.

Conclusion

Clinicians should consider questioning for cocaine use particularly amongst young adults who present with cardiac symptoms. More epidemiological work is required to quantify the effect of cocaine upon both arterial and venous clotting mechanisms.

Toxins

Exposures to toxins are prevalent, frequently complicate surgical emergencies, and impact critical care. A fundamental understanding of pathophysiologic principles and management strategies is essential for the anesthesiologist frequently responsible for the acute care of patients who have toxicologic exposures. Given their pervasiveness and ability to confound the clinical presentations in the perioperative or intensive care setting, substances of abuse and asphyxiants warrant particular attention and a high degree of vigilance.

An overview of non-cardiac cocaine toxicity

Cocaine use in the United States continues to be a significant problem. Cocaine use is responsible for approximately 143,000 Emergency Department visits annually. The cardiac effects of cocaine are well known and much is written on this topic; this is beyond the scope of this article. Cocaine use is also responsible for a variety of non-cardiac, systemic complications, which it is our purpose to review. Multiple systemic effects of cocaine are seen with both acute and chronic use. These systems include: psychological and psychiatric, neurological, renal, pulmonary, gastrointestinal, obstetrical, and otolaryngological.

Cocaine activates calcium/calmodulin kinase II and causes cardiomyocyte hypertrophy

Cardiac hypertrophy occurs in as many as 47% of normotensive individuals who chronically use cocaine. We investigated the effects of cocaine, in concentrations commonly found in chronic cocaine users, on calcium/calmodulin kinase (CaMK), and whether cocaine can activate CaMK, increase cardiac myocyte protein expression, and cause cardiac hypertrophy in this manner. In series I to III, 0 (control) or cocaine in concentrations of 10 to 10 mol/L was added to cultured adult rat cardiac ventricular myocytes to determine by Western blots and by P incorporation the optimal treatment time and the optimal dose for CaMK activation. In series I, cocaine, 10 mol/L, increased myocyte CaMKII translocation from myocyte soluble to particulate fractions by > or =73 +/- 9% (P < 0.01) in comparison with controls but did not cause the translocation of CaMKI or CaMKIV. In series II and III, cocaine treatment of myocytes for 15 minutes increased maximal CaMKII activity by 86.5 +/- 13.3% (P < 0.001) and a cocaine dose of 5 x 10 mol/L increased CaMKII activity by 169.5 +/- 18.1% (P < 0.001). In series IV we measured by silver staining beta-myosin heavy chain protein (beta-MHC) expression in myocytes before and after cocaine and also CaMK inhibition with KN-62 (1-[N,O-bis-(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine). In these experiments, cocaine, 5x10 mol/L, increased myocyte protein concentration by 29.2 +/- 2.8%, and beta-MHC by 93.2 +/- 8.8% (P < 0.001). In series V and VI, cocaine effects on calcium currents (ICa) and intracellular Ca ([Ca]i) were determined before and after CaMK inhibition with KN-62 in rat myocytes. Cocaine, 10 mol/L, enhanced ICa peak amplitude in a voltage-dependent manner (by 173.9 +/- 14.9% at -20 mV and by 38.4 +/- 6.9% at 0 mV P < 0.01). Cocaine, 10 to 10 mol/L, in series VI promoted Ca transients from myocyte sarcoplasmic reticulum and increased [Ca]i to 607 +/- 141 x 10 mol/L (P < 0.05). KN-62 decreased cocaine-induced myocyte protein expression by 76.6%, and beta-MHC by 66.2% (P < 0.01) and significantly decreased cocaine-induced Ca transients and [Ca]i. We conclude that CaMKII activation is an important mechanism whereby cocaine can cause myocyte hypertrophy.