The pathophysiology of cocaine abuse

Severe Cocaine-Induced Midline Destructive Lesions (CIMDL) Leading to Orbital Apex Syndrome and Peripheral Ulcerative Keratitis

PURPOSE

To describe a case of cocaine-induced midline destructive lesions (CIMDL) associated with ocular autoimmune disease.Methods: Observational case report.

RESULTS

A 45-year-old man with history of chronic osteolytic sinusitis due to cocaine abuse presented with sudden vision loss in right eye. Ophthalmic examination revealed fixed right mydriasis with extraocular movements limitation and optic disc swelling. Computed tomography showed an orbital infiltrating mass. The diagnosis of orbital-apex syndrome secondary to CIMDL was established. Steroids and antibiotics therapy were started without vision improvement. At 6-months follow-up, a corneal ulcer with characteristics of peripheral ulcerative keratitis (PUK) was evidenced, coinciding with an upper respiratory bacterial infection.

CONCLUSIONS

CIMDL and PUK share common pathogenic pathways, with implication of autoimmune factors and exposure to infective antigens. We hypothesized that chronic cocaine use, along with persistent bacterial infection, could have triggered an inflammatory reaction, which contributed to CIMDL development and the appearance of PUK.

Role of Mitochondrial Dynamics in Cocaine's Neurotoxicity

The dynamic balance of mitochondrial fission and fusion maintains mitochondrial homeostasis and optimal function. It is indispensable for cells such as neurons, which rely on the finely tuned mitochondria to carry out their normal physiological activities. The potent psychostimulant cocaine impairs mitochondria as one way it exerts its neurotoxicity, wherein the disturbances in mitochondrial dynamics have been suggested to play an essential role. In this review, we summarize the neurotoxicity of cocaine and the role of mitochondrial dynamics in cellular physiology. Subsequently, we introduce current findings that link disturbed neuronal mitochondrial dynamics with cocaine exposure. Finally, the possible role and potential therapeutic value of mitochondrial dynamics in cocaine neurotoxicity are discussed.

Stability of Cocaine, Opiates, and Metabolites in Dried Saliva Spots

Drug abuse still represents a global problem, and it is associated with an increased risk of diseases, injuries, and deaths. Cocaine (COC) and opiates are the most abused drugs and account for a significant number of fatalities. Therefore, it is important to develop methods capable of effectively identifying and quantifying these substances. The present study aims to evaluate the long-term stability of COC, ecgonine methylester (EME), benzoylecgonine (BEG), cocaethylene (COET), norcocaine (NCOC), morphine (MOR), codeine (COD) and 6-monoacetylmorphine (6-MAM) in oral fluid samples. The analytes of interest were isolated from the matrix (50 µL) using the dried saliva spots (DSS) sampling approach and were subsequently analyzed by gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). The parameters that could influence the stability of the target compounds were studied, and these were storage temperature, light, use of preservatives (and respective concentrations), and time. The effects of each parameter were evaluated using the design of experiments (DOE) approach. The stability of the target analytes was improved when the DSS were stored at room temperature, in the presence of light and using 1% sodium fluoride. The best conditions were then adopted for the DSS storage and long-term stability was assessed. COD was only stable for 1 day, EME was stable for 3 days, COC, COET, NCOC and 6-MAM were stable for 7 days, MOR for 14 days and BEG remained stable throughout the study (136 days). This is the first study that evaluates the stability of these compounds in oral fluid samples after application in DSS cards, and optimizes the conditions in order to improve their stability.

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

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

Cocaine and Cardiotoxicity: A Literature Review

Long-term cocaine use, as well as acute cocaine use, is associated with adverse cardiovascular consequences, including arrhythmias, angina, myocardial infarction, heart failure, and other conditions. Over the long term, cocaine can result in structural changes to the heart such as increased left-ventricular mass and decreased left-ventricular end-diastolic volume. Patients arriving with cocaine-associated cardiovascular complaints may not be forthcoming about their cocaine or polysubstance abuse or may be unresponsive. The role of beta-blockers, a first-line treatment for many forms of heart disease, is controversial in this population. Cocaine is a powerful sympathomimetic agent, and it was thought that beta-blockade would result in unopposed alpha-adrenergic stimulation and adverse consequences. A number of small, single-center, retrospective and observational studies suggest that beta-blockers may be safe, effective, and beneficial in this population. Further study is needed to clarify the role of beta-blockers in this population. 

Cocaine Abuse: An Attack to the Cardiovascular System-Insights from Cardiovascular MRI

Cocaine is the most commonly used illicit drug in the European Union. Its cardiac effects are numerous and diverse, both in acute and chronic abuse, and include myocardial infarction, myocarditis, catecholamine-induced cardiomyopathy, and chronic cardiomyopathy (subclinical, hypertrophic, and dilated phases). Their clinical manifestations are vastly overlapping, and differential diagnosis should be performed using a thorough diagnostic workup featuring clinical history, laboratory tests, electrocardiography, stress test, noninvasive imaging modalities, and coronary angiography. Cardiac MRI has the unique ability of in vivo tissue characterization. This unique feature can play a pivotal role in the differential diagnosis through proper characterization of the myocardial tissue. Especially in acute settings, cardiac MRI makes it possible to distinguish between cocaine-induced myocardial infarction, cocaine-induced myocarditis, and catecholamine-induced cardiomyopathy. Conversely, in chronic cardiomyopathy, cardiac MRI permits evaluation of ventricular function and myocardial tissue, allowing the investigation of the underlying cause. On the one hand, assessing the ventricular function permits differentiation among subclinical, hypertrophic, and dilated phases of chronic cardiomyopathy; on the other hand, cardiac MRI could classify the causes underlying remodeling, including chronic ischemic injury, chronic myocarditis, and cardiac motion impairment. This review analyzes the relationship between pathophysiology, histology, and disease using the existing literature on cardiac MRI cocaine abuse evaluation. © RSNA, 2019.

Unintentional drug overdose deaths involving cocaine among middle-aged and older adults in New York City

BACKGROUND

Cocaine is commonly involved in unintentional drug poisoning (overdose) deaths, accounting for 46% of overdose deaths in New York City (NYC) in 2016. However, little research exists regarding cocaine use by middle-aged and older adults, who are more likely than younger individuals to have underlying cardiovascular disease (CVD) and therefore, may be at increased risk for the adverse health consequences of cocaine.

METHODS

We conducted a retrospective analysis of unintentional drug overdose deaths of middle-aged and older NYC residents age 45-84 from 2000 to 2016 using two linked sources, NYC death certificates and toxicology results from the Office of the Chief Medical Examiner.

RESULTS

From 2000 to 2016, there were 6061 unintentional drug overdose deaths among New Yorkers age 45-84. Of those, cocaine was involved in 53% (n = 3183). Co-occurring opioid involvement (fentanyl, heroin, methadone, or opioid analgesics) among deaths involving cocaine was common (58%). Compared to decedents of non-cocaine involved overdose, decedents of cocaine-involved overdose were more likely to be male and non-Latino Black. Multivariable analysis showed that adults age 45-54 (adjusted odds ratio [AOR] = 1.34, 95% 1.05, 1.70), males (AOR = 1.30, 95% CI 1.15, 1.46), Bronx residence (AOR = 1.29, 95% CI 1.08, 1.54), and non-Latino black race/ethnicity (AOR = 2.37, 95% CI 2.07, 2.72) were independently associated with cocaine-involved overdose.

CONCLUSION

Characteristics of decedents of cocaine-involved overdose overlap with populations with high CVD burden in NYC. Studies are needed to better understand the risks of cocaine among adults with underlying CVD.

Neurotoxicology and drug-related disorders

Neuropsychiatric disorders caused by toxic substances pose a great diagnostic challenge due to the large variety of changes caused in the central and peripheral nervous system. The pathogenetic mechanisms at work are multifaceted and partly not solved. In human drug abusers (cannabis, opiates, cocaine, amphetamines, methamphetamine and "designer drugs"), a broad spectrum of central nervous system alterations are observed including infarction, intracerebral and subarachnoidal hemorrhage, hypoxic-ischemic leukoencephalopathy, infections, neuronal loss, specific astroglial and microglial reaction patterns, and vascular changes, including the endothelial cell as well as the basal lamina.

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.

Inhibition by cocaine of G protein-activated inwardly rectifying K+ channels expressed in Xenopus oocytes

Cocaine, a commonly abused psychostimulant, interacts with not only transporters for dopamine, serotonin and norepinephrine but also several receptors and channels. However, the molecular mechanisms underlying the various effects of cocaine remain to be clarified. Using the Xenopus oocyte expression assay, we investigated the effects of cocaine on G protein-activated inwardly rectifying K+ (GIRK) channels, which regulate neuronal excitability and the heart rate. In oocytes injected with mRNAs for GIRK1/GIRK2, GIRK2 or GIRK1/GIRK4 subunits, cocaine reversibly reduced basal GIRK inward currents. The inhibition by cocaine at the toxic levels was concentration-dependent, but voltage-independent and time-independent during each voltage pulse. However, methylphenidate, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) at their toxic concentrations had little effect on the channels. Additionally, Kir1.1 and Kir2.1 channels were insensitive to all of the drugs. The inhibition by cocaine, which exists mainly in a protonated form at pH 7.4, was not affected by extracellular pH 9, at which the proportion of the uncharged form increases, suggesting the inhibition by both forms with similar effectiveness, and at physiological pH the effect being predominantly due to the protonated cocaine. Our results suggest that inhibition of GIRK channels by cocaine may contribute to some of its toxic effects.

Comparison of pramipexole and amisulpride on alertness, autonomic and endocrine functions in healthy volunteers

RATIONALE

In a previous study in healthy volunteers, the anti-Parkinsonian drug pramipexole caused sedation and pupil dilatation, consistent with the stimulation of inhibitory D(2)/D(3) autoreceptors on the ventral tegmental area dopaminergic neurones. The sedation may be related to the removal of the dopaminergic excitation of the locus coeruleus (via the meso-coerulear pathway), whereas the pupil dilatation may be due to the removal of the dopaminergic excitation of the Edinger-Westphal nucleus (via a putative meso-pupillomotor pathway).

OBJECTIVES

We investigated the hypothesis that amisulpride, a D(2)/D(3) receptor antagonist, would have effects opposite to those of pramipexole on alertness, pupillary and endocrine functions.

MATERIALS AND METHODS

Pramipexole (0.5 mg), amisulpride (50 mg), and their combination were administered to 16 healthy males in a balanced, cross-over, double-blind design. Tests included measures of alertness (Pupillographic Sleepiness Test, critical flicker fusion frequency, visual analogue scales), pupillary functions (resting pupil diameter, light and darkness reflex responses), non-pupillary autonomic functions (heart rate, blood pressure, salivation, core temperature), and endocrine functions [blood concentrations of prolactin, growth hormone (GH) and thyroid stimulating hormone (TSH)]. Data were analysed by ANOVA.

RESULTS

Pramipexole reduced alertness and pupillary light reflex response amplitude, tended to reduce core temperature, reduced prolactin levels and increased GH levels. Amisulpride reduced pupil diameter, increased the amplitude of the light reflex response and prolactin and TSH levels.

CONCLUSIONS

The opposite effects of pramipexole and amisulpride on alertness, pupillary function and pituitary hormone levels are consistent with their interactions with inhibitory D(2)/D(3) receptors on VTA neurones and in the tuberoinfundibular system.

Prenatal cocaine alone and combined with nicotine alters ANG II and IGF-1 induced left atrial contractions in aging male offspring

Prenatal cocaine or nicotine affects inotropic activity in the hearts of rat offspring. However, the long-term consequence of this exposure on the cardiac response to hormonal challenge is unknown. We assessed the inotropic effects of angiotensin II (ANG II) and insulin-like growth factor 1 (IGF-1) in the left atria of 19.0-24.5 month-old male rats exposed on gestation days 8-21 to 1 of 6 treatments: low cocaine (LC) (20 mg/kg) or high cocaine (HC) (40 mg/kg); 20 mg/kg cocaine and high nicotine (5 mg/kg nicotine) (LC/HN); 40 mg/kg cocaine and low nicotine (2.5 mg/kg nicotine) (HC/LN); pair fed: yoked to HC (PF); saline: injection of 0.9% NaCl (SAL). Isometric contractions were assessed by electrical stimulation of isolated left atria superfused with Tyrode solution (control) to which ANG II (10-7 mol/L, 20 min) and IGF-1 (10-8 mol/L, 20 min) in the presence of ANG II were added sequentially. Offspring in all cocaine groups showed a higher peak tension development (PTD) to ANG II than PF controls. This increase in PTD was attenuated by subsequent addition of IGF-1 in all except HC offspring. However, with the HC/LN combination the IGF-1 effect on PTD was again evident. The velocities of contraction and relaxation were positively affected by ANG II only in the combined prenatal drug groups; IGF-1 reduced only contraction velocity. Our data demonstrate that IGF-1 reverses the positive inotropic effect of ANG-II in atrial muscle of aging rats and that gestational exposure to only high doses of cocaine eliminates this protective response. It appears that combined prenatal exposure to cocaine and nicotine does not exacerbate the decline in cardiac function and responsiveness to inotropic drugs seen in the aging heart.

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

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