Cocaine-induced alterations in prostaglandin production in rabbit aorta

Role of Microglia in Psychostimulant Addiction

The use of psychostimulant drugs can modify brain function by inducing changes in the reward system, mainly due to alterations in dopaminergic and glutamatergic transmissions in the mesocorticolimbic pathway. However, the etiopathogenesis of addiction is a much more complex process. Previous data have suggested that microglia and other immune cells are involved in events associated with neuroplasticity and memory, which are phenomena that also occur in addiction. Nevertheless, how dependent is the development of addiction on the activity of these cells? Although the mechanisms are not known, some pathways may be involved. Recent data have shown psychoactive substances may act directly on immune cells, alter their functions and induce various inflammatory mediators that modulate synaptic activity. These could, in turn, be involved in the pathological alterations that occur in substance use disorder. Here, we extensively review the studies demonstrating how cocaine and amphetamines modulate microglial number, morphology, and function. We also describe the effect of these substances in the production of inflammatory mediators and a possible involvement of some molecular signaling pathways, such as the toll-like receptor 4. Although the literature in this field is scarce, this review compiles the knowledge on the neuroimmune axis that is involved in the pathogenesis of addiction, and suggests some pharmacological targets for the development of pharmacotherapy.

Cocaine-Associated Myocardial Infarction

Myocardial ischaemia and infarction has become a well-recognized sequelae of cocaine use. The possibility of recent cocaine use should be assessed in patients with potential myocardial ischaemia because the treatment of patients with myocardial ischaemia related to cocaine differs from that of patients with myocardial ischaemia unrelated to cocaine. Patients with cocaine-associated myocardial ischaemia should receive initial treatment with benzodiazepines to decrease central adrenergic stimulation. Aspirin should be used to reduce thrombus formation, and nitroglycerin to reverse coronary vasoconstriction. Patients with continued ischaemia can be treated with either low doses of phentolamine, or verapamil. If ischaemia continues after treatment with these agents mechanical reperfusion or thrombolytic therapy should be considered depending upon the clinical circumstances. Patients with myocardial ischaemia secondary to cocaine should not receive treatment with beta adrenergic antagonists as these agents enhance coronary vasoconstriction thereby worsening ischaemia.

Drug-induced Raynaud's phenomenon: beyond β-adrenoceptor blockers

AIM

Drug-induced Raynaud's phenomenon (RP) has long been associated with the use of different drugs, including cancer chemotherapy or β-adrenoceptor blockers. However, sources report extremely variable prevalence and the level of evidence for each class is heterogeneous. Moreover, new signals are emerging from case reports and small series. Our objective was therefore to review available evidence about this adverse drug effect and to propose a mechanistic approach of drug-induced RP.

METHODS

A systematic review of English and French language articles was performed through Medline (1946-2015) and Embase (1974-2015). Further relevant papers were identified from the reference lists of retrieved articles.

RESULTS

We identified 12 classes of drugs responsible for RP, with a variety of underlying mechanisms such as increased sympathetic activation, endothelial dysfunction, neurotoxicity or decreased red blood cell deformability. Cisplatin and bleomycin were associated with the highest risk, followed by β-adrenoceptor blockers. Recent data suggest a possible involvement of tyrosine kinase inhibitors (TKI), through an unknown mechanism.

CONCLUSION

Drug-induced RP is a probably underestimated adverse drug event, with limited available evidence regarding its prevalence. Although rare, serious complications like critical digital ischaemia have been reported. When these treatments are started in patients with a history of RP, careful monitoring must be made and, if possible, alternative therapies that do not alter peripheral blood flow should be considered.

A review on renal toxicity profile of common abusive drugs

Drug abuse has become a major social problem of the modern world and majority of these abusive drugs or their metabolites are excreted through the kidneys and, thus, the renal complications of these drugs are very common. Morphine, heroin, cocaine, nicotine and alcohol are the most commonly abused drugs, and their use is associated with various types of renal toxicity. The renal complications include a wide range of glomerular, interstitial and vascular diseases leading to acute or chronic renal failure. The present review discusses the renal toxicity profile and possible mechanisms of commonly abused drugs including morphine, heroin, cocaine, nicotine, caffeine and alcohol.

Cocaine and the heart

The use of cocaine may be associated with either acute or chronic toxicity, and approximately 5% to 10% of emergency department visits in the United States are believed to be secondary to cocaine usage. Chest pain is the most common cocaine-related medical problem, leading to the evaluation of approximately 64,000 patients annually for possible myocardial infarction, of which approximately 57% are admitted to the hospital, resulting in an annual cost greater than $83 million. There is a plethora of cocaine-related cardiovascular complications, including acute myocardial ischemia and infarction, arrhythmias, sudden death, myocarditis, cardiomyopathy, hypertension, aortic ruptures, and endocarditis. There is no evidence to suggest that preexisting vascular disease is a prerequisite for the development of a cocaine-related cardiovascular event, although it may be a potentiating factor, as may be nicotine and alcohol.

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.

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-induced renal disease

Cocaine has anaesthetic, vasoconstrictive and CNS stimulatory effects. Presently, it is used clinically as a local anaesthetic and abused as a recreational drug. It has been implicated in both acute and chronic renal failure and has been reported to affect every aspect of the nephron. This article will review the spectrum of cocaine-induced kidney disease and attempt to give insight into the pathophysiological mechanisms involved.

Chronic prenatal exposure to cocaine alters cerebrovascular responses in newborn pigs

Maternal cocaine abuse may increase the incidence of perinatal asphyxia. In nonexposed asphyxiated neonates, decreased cerebrospinal fluid (CSF) cAMP concentrations are associated with poor neurological outcome. On the other hand, cocaine increases central nervous system (CNS) cAMP. Therefore, we hypothesized that in utero cocaine exposure may increase brain cAMP and thereby preserve cerebrovascular responses to cAMP-dependent stimuli following asphyxia. Pregnant pigs received either cocaine (1 mg/kg, i.v.) twice weekly during the last trimester or normal saline vehicle (sham-control) and were allowed to deliver vaginally at term. Cranial windows were implanted in the newborn pigs within the first week of life and used to collect CSF for cAMP determinations and to assess changes in pial arteriolar diameters (PAD). In the first part of the study, pial arteriolar responses to different vasodilator and vasoconstrictor stimuli were evaluated in piglets prior to asphyxia (n = 20). In newborn pigs exposed to cocaine, cerebrovascular responses to hypercapnia and norepinephrine were significantly exaggerated compared to controls. Then, piglets were randomly selected for the second part of the study that involved prolonged asphyxia (n = 12). In cocaine-exposed but not sham-control piglets, CSF cAMP increased markedly during asphyxia. In the sham piglets, but not the cocaine-exposed piglets, CSF cAMP fell progressively below the baseline during recovery. Cerebrovascular reactivity to cAMP-dependent stimuli (hypercapnia and isoproterenol) was preserved during recovery from asphyxia in the cocaine-exposed piglets but significantly attenuated in the sham controls. We conclude that piglets with chronic prenatal exposure to cocaine show exaggerated cerebrovascular responses to vasogenic stimuli and preserved cAMP-dependent cerebral vasoreactivity following asphyxia.

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.

Effects of cocaine on the coronary arteries

BACKGROUND

A number of studies have documented myocardial ischemia and infarction associated with cocaine use. Mismatch between myocardial oxygen supply and demand from cocaine-induced vasoconstriction and increased myocardial workload are often invoked as the major postulated mechanism by which cocaine induces myocardial ischemia. This article reviews the literature studying the effects produced by cocaine on the coronary arteries to provide insight into the various pathophysiologic mechanisms by which cocaine triggers acute cardiac ischemia or infarction.

METHODS

We reviewed the published literature describing the effects of cocaine on the coronary arteries. A MEDLINE search of English language articles published between 1985 and 2000 was performed. Key words included coronary arteries, coronary vasoconstriction, vasospasm, coronary vasodilation, cardiac vasculature, myocardial ischemia, platelets, thrombosis, and cocaine. Both animal and human studies were included. The bibliographies of identified articles were also explored for additional sources of information.

RESULTS

A recreational dose of cocaine increases the heart rate by approximately 30 beats/min. It also increases the blood pressure by 20/10 mm Hg. These increases are modest, are equivalent to mild exercise, and are not believed to be sufficient to result in myocardial ischemia in the majority of cases. Animal and human studies have documented cocaine-induced early coronary artery vasodilation as shown by a decrease in coronary perfusion pressure ranging from 13% to 68%. This was followed by a more sustained vasoconstriction demonstrated by a decrease in epicardial coronary artery diameter ranging from 5% to 30% with various doses of cocaine by various methods of administration. These changes alone are also an unlikely explanation for cocaine-induced myocardial ischemia. Therefore neither increases in myocardial workload nor hemodynamic changes are sufficient to explain cocaine-induced myocardial ischemia. However, evidence also exists that cocaine activates platelets and promotes thrombosis, resulting in intracoronary thrombus formation. Cocaine may also promote premature and more severe coronary atherosclerosis.

CONCLUSION

The etiology of cocaine-induced myocardial ischemia is complex and is likely to be multifactorial. It appears to be the result of coronary artery vasoconstriction, intracoronary thrombosis, and accelerated atherosclerosis.

Cocaine activates platelets and increases the formation of circulating platelet containing microaggregates in humans

OBJECTIVE

To determine whether there is evidence of platelet activation following in vivo cocaine administration in humans, as cocaine abuse is associated with myocardial infarction and stroke, and platelet activation leading to thrombosis is a possible mechanism.

SETTING

University hospital.

DESIGN AND SUBJECTS

Following a randomised, double blind crossover design, 14 healthy volunteers were studied twice, receiving cocaine (2 mg/kg intranasally) once and placebo once. Flow cytometric analysis of P-selectin expression (an alpha granule membrane protein found on the surface of activated platelets), quantification of the platelet specific proteins platelet factor 4 and beta thromboglobulin, and measurement of platelet containing microaggregate and platelet microparticle (fragment) formation were used to assess platelet activation. Circulating von Willebrand factor antigen (vWF) was measured to evaluate a possible role of endothelial stimulation concurrent with platelet activation.

RESULTS

There was an increase in both platelet factor 4 (mean (SD), 16 (7) to 39 (22) IU/ml, p = 0. 04) and beta thromboglobulin (70 (20) to 98 (26) IU/ml, p < 0.01) at 120 minutes following cocaine administration. Platelet containing microaggregate formation was increased at 40 minutes (from 47 (3.2)% to 54 (2.0)%, p < 0.001) and 80 minutes (55 (2.5)%, p = 0.04). Bleeding time decreased following cocaine from 10 (1) to 9 (1) minutes (p = 0.07). No changes in any of the measured variables were noted following placebo administration.

CONCLUSIONS

Cocaine exposure causes platelet activation, alpha granule release, and platelet containing microaggregate formation. These data support the view that cocaine, even at the relatively low doses commonly self administered by occasional abusers, may promote thrombosis and predispose healthy individuals to ischaemic events. Platelet inhibitors should be considered early in any patient with suspected cocaine related ischaemia.

Cocaine and the kidney: a synthesis of pathophysiologic and clinical perspectives

Cocaine abuse has reached epidemic proportions in the United States, and several forms of renal disease have been associated with this widespread use. The hemodynamic actions of cocaine, as well as its effects on matrix synthesis, glomerular inflammation, and glomerulosclerosis, may contribute to renal injury. Cocaine abuse has been associated with various forms of acute renal failure and acid-base and/or electrolyte disorders and may also have a role in the progression of chronic renal failure to end-stage renal disease. In utero exposure to cocaine has been associated with urogenital tract anomalies. Medical management of a hypertensive emergency caused by acute cocaine toxicity requires a multisystem approach, with close monitoring of cardiac, neurological, and renal functions.

Echocardiographic Diagnosis of Biventricular Thrombi in a Cocaine-Induced Myocardial Infarction

We present the case of a patient with a biventricular myocardial infarction induced by cocaine and a large left and a smaller right ventricular apical thrombus. Serial multiplane transesophageal echocardiography was used to document the morphological course of the thrombi during anticoagulation therapy over a period of 6 weeks.

Cocaine-induced peripheral vascular occlusive disease--a case report

Two patients with cocaine-induced peripheral vascular occlusive disease are presented. A 37-year-old man was admitted to the hospital for evaluation of severe pain and numbness of his feet. He had used cocaine prior to admission. Arteriography showed bilateral occlusions of superficial femoral, popliteal, and trifucation arteries. Despite repeated infusions of urokinase, he developed progressive bilateral gangrene of both legs necessitating bilateral below-knee amputations. The second patient developed similar symptoms after smoking cocaine. Arteriography showed vasospasm bilaterally from the iliac arteries distally. I.v. nitroglycerin infusion caused resolution of the vasospasm and ischemic symptoms.

Cocaine-induced increase of Mn-SOD in adult rat liver cells

Cultured adult rat liver cells (non-induced) were exposed to two different concentrations (2 microg/ml and 4 microg/ml) of cocaine-HCI for 1-3 hours. Cocaine-treated rat liver cells showed a significant increase in manganese superoxide dismutase (Mn-SOD) activity with time. Coinciding the rise in Mn-SOD activity was the Mn-SOD mRNA transcript, which also demonstrated a time-dependent elevation in its level (p<0.005). At the end of 1 and 3 hr. of cocaine exposure, the increase in Mn-SOD activity was 23% (p<0.05) and 39% (p<0.005), respectively. In contrast, activities of catalase (CAT) and glutathione peroxidase (GSH-px) were significantly diminished. Induction of Mn-SOD mRNA by cocaine (4 microg/ml) was inhibited by actinomycin D (4 microM), revealing that the up regulation of Mn-SOD involved transcriptional activation. The increase in Mn-SOD was accompanied by a decrease in liver cell integrity, indicated by increased lactate dehydrogenase (LDH) release by rat liver cells. These results suggest that antioxidant enzymes may play a critical role in cocaine-induced liver injury.

Acute and chronic cocaine exposure can produce myocardial ischemia and infarction in Yucatan swine

The purpose of this study was to determine whether the acute and chronic administration of cocaine could induce myocardial infarction. Twenty-five minipigs were studied before and 4 months after balloon angioplasty of the left anterior descending artery (LAD) and balloon denudation of the left circumflex artery (LCx). Minipigs received cocaine in the initial and in the 4-month study (0.1, 0.5, and 3 mg/kg i.v.). Minipigs were randomized to group I (high-cholesterol diet + daily cocaine; 500 mg i.m.; n = 8), group II (high-cholesterol diet + no i.v. cocaine; n = 5), group III (chow diet + daily cocaine; 500 mg i.m.; n = 6), group IV (chow diet + no i.v. or i.m. cocaine; n = 6). In vivo, coronary flow significantly decreased and vascular resistance significantly increased after the administration of cocaine. Histamine significantly decreased the luminal diameters (LAD and LCx) in groups I, II and III. There were a total of five acute and 16 chronic infarctions among the three groups that received either short- or long-term cocaine; however, no infarct occurred in group IV. The combination of daily cocaine abuse with a cholesterol-rich diet enhanced coronary vasoreactivity in vivo and in vitro. We conclude that long-term or sporadic cocaine abuse can induce myocardial infarction.

Endothelium-dependent vasorelaxation is impaired in cocaine arteriopathy

OBJECTIVES

This study sought to assess endothelium-dependent vasorelaxation in long-term users of cocaine.

BACKGROUND

Cocaine use has been associated with myocardial infarction, stroke and intestinal infarction. Previously demonstrated effects of the drug, including increased heart rate and blood pressure and increased vascular tone, do not explain the sporadic nature of these vascular events or the occurrence of ischemia remote from acute administration. Abnormal endothelial function could contribute to focal vasospasm and thrombosis and predispose to premature atherosclerosis, all of which have been demonstrated in cocaine users with myocardial infarction.

METHODS

Using plethysmography, we studied the change in forearm blood flow in response to intraarterial acetylcholine and nitroprusside in 10 long-term cocaine users and 13 control subjects of similar age who had not used cocaine; sample size was based on a 70% power to detect a 20% reduction in flow with acetylcholine between subjects and control subjects. Using graded doses of intracoronary acetylcholine (from 10(-9) to 10(-6) mol/liter), we studied a second group of 10 cocaine users with angiographically normal or near-normal arteries.

RESULTS

Mean forearm blood flow during acetylcholine infusion was significantly lower in cocaine users than in control subjects (p = 0.02). During nitroprusside infusion, there was no difference (p = 0.2) between cocaine users and control subjects. Cigarette smoking did not explain the differences between cocaine users and control subjects. Acetylcholine elicited coronary vasoconstriction in 8 of 10 subjects.

CONCLUSIONS

We conclude that endothelium-dependent vasorelaxation is impaired in long-term users of cocaine.

Cocaine does not affect prostacyclin, thromboxane or prostaglandin E production in human umbilical veins

Vasoactive prostaglandins have been reported to mediate umbilical/placental blood flow in humans. Since it has been suggested that cocaine exerts its teratogenic action via vasoconstriction and a corresponding reduction in blood flow, it is reasonable to hypothesize that cocaine influences the vasoactive prostaglandins such that blood flow would be affected. The purpose of this study, therefore, was to determine the effects of cocaine on the vasoactive prostaglandins prostacyclin, thromboxane, and prostaglandin E, using human umbilical veins. Prostacyclin (PGI2), thromboxane (TXA2), and prostaglandin E (PGE) levels were measured from human umbilical veins collected at term. The veins were perfused in a closed system with either a 50 micrograms/ml, a 100 micrograms/ml, a 200 micrograms/ml, or a 400 micrograms/ml cocaine solution for 60 min, and the prostaglandins were measured by radioimmunoassay of their stable metabolites. Data were analyzed by ANOVA, and post-hoc analyses were performed by Fisher's Protected Least Significant Difference Test. Cocaine did not influence PGI2, TXA2, or PGE production (Ps > 0.05) in this series of studies. Thus, contraction of human umbilical vessels and decreased blood flow in human umbilical vessels does not appear to be mediated by changes in the vasoactive prostaglandins.

Chronic intestinal ischemia caused by intravenous cocaine use: report of two cases and review of the literature

Chronic mesenteric ischemia caused by thrombosis of large visceral arteries due to cocaine abuse are reported in two young women. Both cases were managed successfully with visceral revascularization.

Effects of cocaine on human platelet aggregation in vitro

BACKGROUND

A temporal relationship has been established between cocaine ingestion and myocardial infarction, and a cocaine-induced increase in platelet aggregation has been suggested as a possible explanation. However, the mechanisms of cocaine associated coronary thrombosis have yet to be completely elucidated. For this reason, we examined the in vitro effect of cocaine and its metabolites on platelet aggregation.

METHODS

Platelet aggregation was tested by obtaining platelet rich plasma from 42 healthy volunteers and incubating the platelet rich plasma in six concentrations of cocaine (ranging from 1.47 to 2940 nmol) for 10 minutes prior to aggregation with ADP 1 microM. The same procedure was used to test the effect of two cocaine metabolites, benzoylecgonine and ecgonine methyl ester, on platelet aggregation. Abnormal results were confirmed by inducing aggregation with ADP at higher concentrations (2.4 and 10 microM) and with arachidonic acid (624 microM).

RESULTS

At increasing concentrations, cocaine progressively inhibited ADP and arachidonic acid induced platelet aggregation. No effect was seen with benzoyl ecgonine or ecgonine methyl ester as compared to saline.

CONCLUSIONS

These data suggest that under certain conditions cocaine may negatively affect hemostasis by decreasing platelet aggregation.

Cocaine and benzoylecgonine constrict cerebral arteries by different mechanisms

This study was designed to determine possible mechanisms underlying the vasoconstrictor activity of cocaine and its principal metabolite, benzoylecgonine (BE) in cat isolated cerebral arteries. The arteries constricted significantly in response to single doses of cocaine, BE and norepinephrine (NE; (P < 0.05). After 6-OHDA treatment to remove adrenergic nerve endings, NE-induced constrictions were essentially unchanged from those before treatment. Denervated arteries exposed to cocaine dilated significantly (P < 0.05) but those exposed to BE constricted as much as before denervation. Following exposure to prazosin and yohimbine, arterial constrictions to NE and cocaine were significantly reduced from control (P < 0.05) but the BE-induced constriction was unchanged. Ryanodine eliminated the cocaine-induced contraction (P < 0.05) whereas verapamil eliminated the BE response (P < 0.05). These data suggest that while cocaine's vasoconstrictor action may be significantly mediated through adrenergic transmission, BE may act through a mechanism involving calcium (Ca2+) channels. Cocaine levels peak and decline in the body more rapidly than BE levels which can remain detectable for days. This study suggests there may also be different pharmacological mechanisms as well as temporal differences underlying the vasoreactivity of these two substances. Our findings may have implications for pharmacological management of cocaine-induced toxic vascular events.

Nitroglycerin in the treatment of cocaine associated chest pain--clinical safety and efficacy

The optimal medical regimen for the treatment of cocaine associated myocardial ischemia has not been defined. While animal and human data demonstrate the risks of beta-adrenergic blockade, studies in the cardiac catheterization laboratory suggest a beneficial role of nitroglycerin. We performed a prospective multicenter observational study to evaluate the clinical safety and efficacy of nitroglycerin in the treatment of cocaine associated chest pain at six municipal hospital centers. Of 246 patients presenting with cocaine associated chest pain, 83 patients were treated with nitroglycerin at the discretion of the treating physician. Relief of chest pain and/or adverse hemodynamic outcome were the primary endpoints. Baseline comparisons of patients treated with nitroglycerin to those not treated with nitroglycerin found that the treated patients were at higher risk of ischemic heart disease. They were older (36 years vs 32 years, p = 0.0008), more likely to have an ischemic electrocardiogram (27% vs 4%, p < 0.0001), to be admitted (94% vs 40%, p < 0.0001), and to have a discharge diagnosis of ischemic heart disease (41% vs 9%, p < 0.0001). Nitroglycerin was beneficial in 41 patients (49%; 95% CI, 38-60%): 37 patients (45%) had relief or reduction in the severity of chest pain and 4 patients (5%) had other beneficial effects. Only one patient had an adverse outcome (transient hypotension in the setting of a right ventricular infarct). Nitroglycerin is safe and possibly effective in the treatment of cocaine associated chest pain.

Cellular mechanisms of cocaine cardiotoxicity

Although cocaine abuse has been a major drug problem in the United States for over 100 years, it has only been in the last decade that the adverse effects of cocaine on the cardiovascular system have become a serious health issue. The cardiotoxic effects of cocaine are multifactorial and remain a puzzle for investigators to solve. Evidence suggests that cocaine-induced toxic effects on the cardiac and vascular cells include both direct as well as indirect components. In addition, other chemical, physiologic, and environmental factors may further complicate and alter mechanisms and endpoints of cocaine-induced cellular toxicity. In order to fully understand the overall cardiotoxic response to cocaine, the cellular mechanisms and endpoints of toxicity of each of these potentially injurious factors must be identified.

Increased prevalence of aortic fatty streaks in cholesterol-fed rabbits administered intravenous cocaine: the role of vascular endothelium

Several recent postmortem studies suggest an increased prevalence of atherosclerosis in young habitual cocaine abusers. However, little is known about the effects of cocaine abuse on the vascular endothelium and its relationship to atherosclerosis. Therefore, the consequence of chronic administration of intravenous cocaine on the induction of aortic sudanophilia was examined. Male New Zealand White rabbits were fed a 0.5% cholesterol diet for 10 wk. During this period, animals were randomized to receive either cocaine-hydrochloride (0.25 mg/kg) intravenously (n = 17) twice daily; or an equivalent volume of 0.9% physiologic saline, control group (n = 16). Mean values for total circulating leukocytes and platelets and total plasma cholesterol and triglycerides were similar in both groups throughout the protocol. At the completion of the study, aortic sudanophilia was measured and expressed as a percentage of regional involvement (R1 = proximal 4 cm, R2 = middle 6 cm, and R3 = distal 10 cm). Statistical significance among groups was achieved in the proximal thoracic aorta (p = 0.057). No significant differences in sudanophilia were noted in the middle and distal segments. When animals were placed in subgroups according to percent total plaque involvement, there was a significant increased distribution of rabbits with a greater extent of sudanophilia in the cocaine-treated group as compared with control (p = 0.01, chi-square analysis). Immunocytochemical studies using the macrophage-specific and muscle actin-specific monoclonal antibodies demonstrated that sudanophilic areas in both groups were predominantly composed of macrophage-derived foam cells. Evaluation of plaque morphology showed an increase in intimal plaque thickness and in the number of macrophages and smooth muscle cells in cocaine-treated animals; however, group differences were not statistically significant. Because no significant differences were found in the cellular composition of atherosclerotic plaques between groups, further studies were performed to assess the effects of cocaine on the permeability function of cultured endothelial cell monolayers as a possible mechanism of increased sudanophilia. Cocaine (100 microM)-treated endothelial cell monolayers demonstrated an increased permeability to horseradish peroxidase during all time intervals studied (0-6 hr). Permeability differences were statistically significant at 30 min and 1 hr (p = 0.003 and 0.02, respectively). Collectively, these observations suggest that administration of cocaine to cholesterol-fed rabbits increases the prevalence of aortic sudanophilia via at least one possible mechanism involving enhanced vascular permeability.

Cardiotoxic effects of cocaine and anabolic-androgenic steroids in the athlete

Cocaine and anabolic-androgenic steroid abuse have become major drug problems in the United States. Cocaine has been designated as "the drug of greatest national health concern" while as many as 1 million Americans have used or are currently using anabolic-androgenic steroids to promote athletic performance and/or improve physical appearance. Unfavorable cardiovascular events have been linked to both cocaine and anabolic-androgenic steroid abuse in healthy, physically active individuals. Deaths of several United States athletes in 1986 focused attention on the life-threatening cardiovascular consequences of cocaine abuse. Reports of myocardial injury with anabolic-androgenic steroid abuse are anecdotal. Nevertheless, case reports have illustrated the alarming cardiotoxic potential of these steroids in athletes. Anabolic-androgenic steroids were correlated to myocardial infarction in weight lifters and cardiomyopathy in a former professional football player. From the total emergency room episodes where cocaine was mentioned in 1990, approximately 66% of these episodes occurred in young individuals 18-29 years of age. Over 500,000 of the individuals currently taking anabolic-androgenic steroids for nonmedical purposes are high-school children. Because cocaine and anabolic-androgenic steroids are used improperly, more focus needs to be paid to the toxic mechanisms of their adverse effects. Therefore, the purpose of this review is to discuss mechanisms whereby exercise and/or exercise training may alter the cardiovascular responses to these drugs. Furthermore, we would like to illustrate that contrary to the popular belief, acute and chronic abuse of cocaine and anabolic-androgenic steroids have a negative impact on exercise performance.

Risk of intracranial hemorrhage and other adverse outcomes after cocaine exposure in a cohort of 323 very low birth weight infants

We conducted a prospective cohort study of 323 consecutively born very low birth weight infants (< or = 1499 gm) to determine any association between prenatal cocaine exposure and (1) intracranial ultrasonographic abnormalities and (2) other adverse perinatal outcomes. The infants were assigned to either a cocaine-exposed group (n = 86) or a cocaine-nonexposed group (n = 146) on the basis of combined detection methods for prenatal maternal cocaine abuse including maternal history, maternal and infant urine immunoassay (Emit), and meconium analysis (high-performance liquid chromatography and gas chromatography-mass spectrometry). Ninety-one infants were not assigned because of early death before complete testing (n = 80) or missed tests (n = 11). The detected incidence of cocaine exposure in the assigned population was 37% (86/232). Meconium testing with high-performance liquid chromatography and gas chromatography-mass spectrometry was the sole means of detection in 30% (26/86) of cases. The cocaine-nonexposed infants did not differ from the cocaine-exposed infants in the incidence of intraventricular hemorrhage (36% vs 35%), grades III and IV intraventricular hemorrhage (14% vs 14%), or periventricular leukomalacia (4% vs 2%). Adverse outcomes increased by cocaine exposure were abruptio placentae (8% vs 18%; p = 0.046), surgical ligation of a patent ductus arteriosus (1% vs 7%; p = 0.02), and seizures (5% vs 17%; p = 0.004). We conclude that prenatal cocaine exposure does not increase the incidence or severity of intracranial hemorrhage or periventricular leukomalacia but does increase the risk of abruptio placentae, surgical ligation of a patent ductus arteriosus and seizures in very low birth weight infants.