Cocaine

Fate of systemically administered cocaine in nonhuman primates treated with the dAd5GNE anticocaine vaccine

Cocaine use disorders are mediated by the cocaine blockade of the dopamine transporter in the central nervous system (CNS). On the basis of the concept that these effects could be obviated if cocaine were prevented from reaching its cognate receptors in the CNS, we have developed an anticocaine vaccine, dAd5GNE, based on a cocaine analog covalently linked to capsid proteins of an E1(-)E3(-) serotype 5 adenovirus. While the vaccine effectively blocks systemically administered cocaine from reaching the brain by mediating sequestration of the cocaine in the blood, the fact that cocaine also has significant peripheral effects raises concerns that vaccination-mediated redistribution could lead to adverse effects in the visceral organs. The distribution of systemically administered cocaine at a weight-adjusted typical human dose was evaluated along with cocaine metabolites in both dAd5GNE-vaccinated and control nonhuman primates. dAd5GNE sequestration of cocaine to the blood not only prevented cocaine access to the CNS, but also limited access of both the drug and its metabolites to other cocaine-sensitive organs. The levels of cocaine in the blood of vaccinated animals rapidly decreased, suggesting that while the antibody limits access of the drug and its active metabolites to the brain and sensitive organs of the periphery, it does not prolong drug levels in the blood compartment. Gross and histopathology of major organs found no vaccine-mediated untoward effects. These results build on our earlier measures of efficacy and demonstrate that the dAd5GNE vaccine-mediated redistribution of administered cocaine is not likely to impact the vaccine safety profile.

Physical harm due to chronic substance use

Chronic use at high dose of illicit drugs, alcohol and tobacco is associated with physical disease. The relative physical harm of these substances has not been described before, but will benefit the guiding of policy measures about licit and illicit substances. The physical harm of 19 addictive substances (including alcohol and tobacco), consisting of toxicity and the risk and severity of somatic disease (not psychiatric disease) was assessed based on literature data and the professional opinion of experts using scores ranging from 0 (no physical harm) to 3 (very serious physical harm). For alcohol, tobacco and some illicit drugs strong associations between long-term use or use in high dose versus the risk of somatic disease have been described, whereas for other substances such data are not available. Magic mushrooms, LSD and methylphenidate obtained relatively low scores (0.45-0.65) for physical harm, whereas relatively high scores were given for heroin (2.09), crack (2.32), alcohol (2.13) and tobacco (2.10). For cannabis, tobacco, and alcohol the estimated societal disease burden was higher than at individual level. The present ranking solely based on their physical harm was very similar to a previous ranking based on a combination of dependence liability, physical harm and social impairments.

How toxic is cocaine?

The toxicities of cocaine are far-ranging. They include sudden death, acute medical and psychiatric illness, infectious complications, reproductive disturbances, trauma, criminal activities and societal disruption, including child neglect and abuse and lost job productivity. This chapter focuses on the medical complications. Medical complications in general reflect the intense sympathomimetic activities of cocaine ('sympathetic neural storm'). Psychiatric complications include acute anxiety or panic and paranoid psychosis. Cardiovascular complications include arrhythmias and sudden death, acute myocardial infarction, myocarditis, dissecting aneurysm and bowel infarction. Neurological complications include seizure, intracerebral haemorrhage and brain injury due to hyperthermia and/or seizures, and headache. The incidence of medical complications has been estimated using two databases collected prospectively in the United States. In 1989 and 1990 cocaine ranked first in total encounters, major medical complications and drug-related deaths. An attempt was made to assess the intrinsic toxicity of cocaine by computing the incidence of adverse health outcomes per population of drug abusers. Rates of emergency department visits and deaths were 15.1 and 0.5 respectively, per 1000 persons using drugs in the past year. The magnitude of the cocaine problem, while considerable, is relatively small compared with that of cigarette smoking or alcohol abuse.

Formulating policies on the non-medical use of cocaine

The formulation of policy on cocaine, as on any other social issue, involves explicit or implicit cost-benefit analyses with many factors. Cocaine use carries many medical, psychiatric and social risks, and its inherent pharmacological risk of dependence is greater than for other drugs. The reported frequency of these problems has increased exponentially over the past fifteen years. However, current levels of use are decreasing in the general population, though still increasing among certain subpopulations in which it is accompanied by violent crime. On the other hand, the attempt to control use mainly or exclusively by reducing the supply has been of low efficacy and extremely expensive, in both human and monetary terms, for the consuming countries and economically and politically devastating for the producing countries. Yet past experience with other drugs suggests that legalization of cocaine would increase its use substantially. Moreover, legalization runs counter to public sentiment, even in those countries where the law is applied leniently against users and small-scale traffickers. The most practical policy appears to be to maintain prohibition as a sign of social disapproval, but to rely much more heavily on non-coercive measures to reduce demand by strengthening public consensus against all drug use.

Cocaine-associated chest pain

Current estimates establish that more than 30 million people in the United States use cocaine. Cardiovascular complaints commonly occur among patients who present to emergency departments(EDs) after cocaine use, with chest pain the most common complaint in several studies. Although myocardial ischemia and infarction account for only a small percentage of cocaine-associated chest-pain, physicians must understand the pathophysiology of cocaine and appropriate diagnostic and treatment strategies to best manage these patients and minimize adverse outcomes. This article reviews the pharmacology of cocaine, its role in the pathogenesis of chest pain with specific emphasis on inducing myocardial ischemia and infarction, and current diagnostic and management strategies for cocaine-associated chest pain encountered in the ED.

Substance abuse and withdrawal in the intensive care unit. Contemporary issues

Because 36% of intentional injury victims are drug dependent, the association between drug abuse and violence, especially in urban settings, is high. Withdrawal syndromes in ICU patients confuse their clinical management, may be extremely difficult to diagnose, are often lethal, need to be suspected, and should be prophylaxed against; therefore, all ICU patients should be considered to be at high risk for drug or alcohol dependence, should be tested for evidence of such drugs, and should be interviewed (together with their family members) for the presence of drug dependence traits. Appropriate patients should be referred for formal evaluation and treatment. Withdrawal syndromes must be promptly recognized, differentiated from traumatic or metabolic deterioration, and immediately treated. As patients are unique, so is their drug dependence. Individualized withdrawal therapy, not a "one method fits all" approach, works best. The mainstay of most withdrawal therapy is supportive care and benzodiazepine therapy. Also, considering the high rate of multiple intoxicants present in trauma patients, withdrawal can occur from multiple agents in a single patient, further compounding these difficulties. Withdrawal from unusual substances, such as GHB, or from therapeutic interventions (e.g., prolonged opioid or benzodiazepine administration) also must be considered.

Helping your patients beat cocaine addiction. The four dimensions of treatment

Despite public health efforts aimed at curbing the steady increase of drug abuse in this country, many patients continue to require treatment for cocaine addiction. A comprehensive treatment approach requires integration of pharmacologic, psychological, social, and spiritual dimensions, although research is needed to demonstrate the efficacy of such an approach in maintaining abstinence. Primary care physicians' assessment and treatment of their cocaine-addicted patients is a critical initial step on the way to specialized psychiatric and/or other specialized care for addiction and, hopefully, to sustained recovery.

Cocaine-associated dystonic reaction

Dystonic reactions are extrapyramidal motor dysfunctions that result from an insufficient activity of nigrostriatal dopamine and present clinically as spasms of the various muscle groups. Neuroleptic drugs are a known cause of dystonia and are the most frequently encountered trigger. Cocaine use has been associated with dystonias, though much less often. When reported in the setting of a dystonic reaction, cocaine has been described as a predisposing factor for the patient already using neuroleptic agents. Fewer reports of dystonia as a direct result of cocaine use, independent of neuroleptics, are found in the literature. The cases of two acute dystonic reactions secondary to cocaine use are presented, with a discussion of the pathophysiology and treatment alternatives.

Clinical course of crack cocaine body stuffers

STUDY OBJECTIVE

To describe the clinical course of a cohort of patients presenting to the emergency department with acute crack cocaine body-stuffer syndrome.

METHODS

We conducted a retrospective cohort study in the ED of a county hospital with 75,000 visits per year. Our study cohort comprised all patients who presented between January 1993 and April 1995 and who met the definition of a crack cocaine body stuffer. We defined a crack cocaine body stuffer as anyone who admitted to or was strongly suspected of ingesting crack cocaine as a means of escaping detection by authorities, not for recreational purposes or as a means of transporting the drug across borders.

RESULTS

We identified 98 cases; most such patients were brought to the ED by law enforcement agents. Most were male and younger than 30 years. Self-report by patients indicated that the amount of crack cocaine ingested ranged from 1 to more than 15 rocks. Most commonly the drug was unwrapped (28%) or wrapped in a plastic sandwich bag (29%). Generalized seizures developed in 4% of the patients; in all these patients seizures occurred within 2 hours of ingestion. In no patient did dysrhythmias develop. Many patients had minor signs of cocaine intoxication: 54% were tachycardic, 23% were hypertensive, 22% were agitated, and 19% required sedation.

CONCLUSION

Mild cocaine intoxication is common in crack cocaine body stuffers, with seizures occurring within 2 hours of ingestion in a small percentage of patients.

Spontaneous acute subdural hematoma precipitated by cocaine abuse: case report

A novel complication of the illicit use of cocaine, a spontaneous acute subdural hematoma, is described. This case represents another addition to the growing literature on the negative effects of cocaine on the central nervous system. Photographic documentation of the lesion responsible for the hematoma is presented, along with a discussion of the possible pathophysiologic mechanism.

Diagnostic indicators in the early recognition of severe cocaine intoxication

Acute cocaine intoxication is an ever increasing problem in the United Kingdom. Aggressive resuscitation linked to early diagnosis is essential in preventing death. Three cases of severe cocaine toxicity are presented to highlight certain diagnostic indicators in recognising the condition in patients presenting in a collapsed state to the accident and emergency department. Acidosis was a striking feature. The acute management of such patients is supportive and should involve methods to minimize continuing absorption.

Cocaine washed out syndrome in a patient with acute myocardial infarction

We present the case of a 34-year-old woman with cocaine-associated chest pain and hypersomnulence, who, because of her inability to report chest pain, and her comfortable appearance, was admitted to telemetry for a diagnosis of low-probability rule-out myocardial infarction. Her chest pain was incompletely relieved, and she subsequently was transferred to the intensive care unit and ruled in for myocardial infarction. We discuss the clinical syndrome of cocaine-related depressed level of consciousness, and its relationship to evaluation of cocaine-related chest pain.

Cocaine abuse and dependence

Western countries experienced a widespread cocaine epidemic during the 1980s, and the number of frequent users has not declined in this decade. A key factor in the development of this epidemic has been the introduction of "crack," an affordable form of cocaine that appears to be more addicting than the powder. Epidemiologic studies indicate a high incidence of polysubstance abuse among cocaine abusers and probable gender differences in patterns of abuse and response to treatment. An abstinence syndrome has been documented in outpatients after the acute cessation of cocaine; the symptoms perhaps depend on the presence of cues to evoke craving of cocaine and thus are not detected in inpatient settings. Cocaine is a psychostimulant drug that possesses euphorigenic and reinforcing properties. The fact that various animal species self-administer cocaine through the intravenous route provides a reliable animal model for the study of the molecular mechanism of cocaine action and for the characterization of the anatomical substrates responsible for the rewarding properties of the drug. A multisynaptic, allocorticolimbic-accumbens-pallidal circuitry has been identified that seems to play an important role. This pathway may also be part of the neuronal substrates that mediate the reinforcing properties of other classes of abused drugs and, perhaps, motivated behavior in general. Because of this potent reinforcing nature of cocaine in humans, the problem of designing effective therapy for its addiction has not been simply solved. Clinical treatments, guided by animal studies and designed for specific attack of symptoms of the abstinence syndrome, craving and anhedonia, have been tested. To date, only a few agents have proved effective in controlled trials (amantadine, bromocriptine, carbamazepine, and desipramine) and these have limitations of side effects or delayed onset of action. Agents that interact with specific subcomponents of the dopamine system or its connections offer promise for the development of successful agents to treat cocaine abuse and craving in humans.

Acid-base abnormalities associated with cocaine toxicity in emergency department patients

There is little information on the prevalence and clinical presentation of acid-base abnormalities associated with cocaine toxicity. To address these issues, arterial blood gas results were evaluated in 156 cocaine-associated emergency department patient visits. Arterial blood gas results were obtained as part of the patient's clinical assessment. The majority of patients (52%) had a normal pH (7.35 to 7.45). Thirty-three percent of patients were acidotic, with a pH between 6.4 and 7.35. In 33 patients the acidosis was metabolic, with a HCO3- of 14 +/- 6 mmol/L. The acidosis was primarily respiratory in 18 patients, with evidence of hypoventilation. Hypoventilation was generally secondary to chest trauma or decreased mental status. Alkalosis (pH > 7.45) was observed in 15% of patients, and was usually respiratory, as evidenced by tachypnea and a low PCO2. These results indicate that metabolic and respiratory acid-base abnormalities are common during cocaine toxicity. Acidosis and alkalosis were associated with numerous patient presentations, including chest pain, shortness of breath, decreased mental status, trauma, and seizures. Acid-base abnormalities do not appear to be associated with a specific route of cocaine self-administration. Patients with a history of potential cocaine toxicity should be evaluated for acid-base abnormalities.

Clinical pharmacology and toxicology of cocaine

Cocaine abuse has produced a major epidemic health problem in North America in the 1980s. The abuse of cocaine is maintained by the drug's effects on brain reward systems, mediated at least in part by its dopaminergic action. The patterns and consequences of use are best understood by considering the pharmacokinetics (rapid absorption and delivery to the brain, relatively short half-life) and the pharmacodynamics (intense central and peripheral neural stimulation). Cocaine is used therapeutically as a topical and local anaesthetic. Toxicity occurs primarily in cocaine abusers, but also occasionally after therapeutic dosing. Medical complications reflect primarily excessive central nervous system stimulation and excessive vasoconstriction, the latter resulting in severe hypertension and/or organ ischaemia with associated organ injury. Most deaths that result from medical complications of cocaine intoxication are sudden and occur before medical intervention is possible. Other complications of cocaine abuse with severe personal and social consequences include traumatic deaths and injuries, and reproductive disturbances, as well as transmission of infectious diseases, especially AIDS. Cocaine addiction is clearly a problem, although the number of addicts is unknown. Pharmacologic treatment of cocaine addiction has as yet been unsuccessful. Psychosocial approaches remain the mainstay of therapy.

Acute treatment of alcohol and cocaine emergencies

This chapter addresses the acute treatment of alcohol and cocaine. Because of the widespread use of both these drugs, health professionals must recognize the medical complications of alcohol and cocaine abuse and addiction. The biochemistry will be briefly reviewed as an avenue to understand the different treatment targets and modalities.

Cocaine adsorption to activated charcoal in vitro

Although activated charcoal (AC) is commonly used after ingestions of cocaine, the ability of AC to bind with this drug is unknown. We studied binding of cocaine to AC in vitro. Cocaine adsorption to charcoal for AC:drug ratios of 1:1, 2.5:1, and 5:1 at pH 1.2 was 40%, 92%, and 99%, respectively; at pH 8.0, it was 78%, 98%, and 99%, respectively. All means were significantly different (P less than 0.05) versus the control (no AC) at each pH. At the AC:drug ratio of 1:1, there was also significantly greater adsorption of cocaine at pH 8.0 than at pH 1.2. This study shows that AC strongly adsorbs cocaine under both acidic and alkaline conditions.