Cardiac depression induced by cocaine or cocaethylene is alleviated by lipid emulsion more effectively than by sulfobutylether-β-cyclodextrin

Subcellular Effectors of Cocaine Cardiotoxicity: All Roads Lead to Mitochondria-A Systematic Review of the Literature

Cocaine abuse is a serious public health problem as this drug exerts a plethora of functional and histopathological changes that potentially lead to death. Cocaine causes complex multiorgan toxicity, including in the heart where the blockade of the sodium channels causes increased catecholamine levels and alteration in calcium homeostasis, thus inducing an increased oxygen demand. Moreover, there is evidence to suggest that mitochondria alterations play a crucial role in the development of cocaine cardiotoxicity. We performed a systematic review according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) scheme to evaluate the mitochondrial mechanisms determining cocaine cardiotoxicity. Among the initial 106 articles from the Pubmed database and the 17 articles identified through citation searching, 14 final relevant studies were extensively reviewed. Thirteen articles included animal models and reported the alteration of specific mitochondria-dependent mechanisms such as reduced energy production, imbalance of membrane potential, increased oxidative stress, and promotion of apoptosis. However, only one study evaluated human cocaine overdose samples and observed the role of cocaine in oxidative stress and the induction of apoptosis though mitochondria. Understanding the complex processes mediated by mitochondria through forensic analysis and experimental models is crucial for identifying potential therapeutic targets to mitigate or reverse cocaine cardiotoxicity in humans.

Cocaethylene cardiotoxicity in emergency department patients with acute drug overdose

OBJECTIVES

Cocaine use results in over 500,000 emergency department (ED) visits annually across the United States and ethanol co-ingestion is reported in 34% of these. Commingling cocaine with ethanol results in the metabolite cocaethylene (CE), which is metabolically active for longer than cocaine alone. Current literature on the cardiotoxicity of CE compared to cocaine alone is limited and lacks consensus. This study aims to fill this gap in the literature and examine cardiovascular events in cocaine use as confirmed by urine toxicology versus CE exposure.

METHODS

This was a secondary data analysis of a prospective cohort study of adult patients with acute drug overdose at two urban tertiary care hospital EDs over 4 years. Patients with positive urinary cocaine metabolites were analyzed, and outcomes were compared between patients with overdose and confirmed presence of cocaine on urine toxicology (cocaine group) and patients with cocaine and ethanol use (CE group). The primary outcome was cardiac arrest. Secondary outcomes included myocardial injury and hyperlactatemia. Data were analyzed using multivariable regression models.

RESULTS

We enrolled a total of 199 patients (150 cocaine, 49 CE). Rates of cardiac arrest were significantly higher in the CE group compared to cocaine (6.1% vs. 0.67%, p = 0.048). Cocaine was significantly associated with myocardial injury compared to CE exposure (mean initial troponin 0.01 ng/ml vs. 0.16 ng/ml, p = 0.021), while hyperlactatemia was associated with CE exposure (mean initial lactate 4.1 mmol/L vs. 2.9 mmol/L, p = 0.038).

CONCLUSIONS

When compared to cocaine exposure alone, CE exposure in ED patients with acute drug overdose was significantly associated with higher occurrence of cardiac arrest, higher mean lactate concentrations, and lower occurrence of myocardial injury.

Lipid emulsions in the treatment of intoxications by local anesthesics and other drugs. Review of mechanisms of action and recommendations for use

Intravenous lipid emulsions (ILEs) have been used widely for the treatment of local anesthetic (LA) poisoning and have been proposed as a treatment for intoxication by other drugs. However, the degree of evidence for this kind of therapy is not strong, as it comes mostly from clinical cases. The aim of this narrative review is to describe the proposed mechanisms of action for ILEs in poisoning by LA and other drugs and to evaluate recent studies in animals that support the recommendations for their use and the experience in humans that support the use of ILESs in both LA and other drug poisoning. For this purpose, a search was performed in the Embase, Medline and Google Scholar databases covering relevant articles over the last 10 years. In the case of AL poisoning, we recommend applying the protocols dictated by international guidelines, knowing that the degree of evidence is not very high. In poisoning by other drugs, ILEs are recommended in serious situations induced by liposoluble xenobiotics that do not respond to standard treatment.

Intravenous Lipid Emulsion for the Treatment of Perioperative Cocaine Intoxication

Symptomatic cocaine intoxication in the preoperative period is a potentially life-threatening condition, especially before emergent surgery. The anesthesiologist is faced with a dilemma where the patient is deemed unsafe for induction of general anesthesia but also in need of immediate surgical intervention. Cocaine is a local anesthetic and, as such, has been proposed to respond to lipid emulsion treatment as other local anesthetics would. We present a case supporting this statement and review the relevant published literature on the topic.

Relationship between cocaine and cocaethylene blood concentration with the severity of clinical manifestations

BACKGROUND

Poisonings resulting from the abuse of drugs currently represent a serious problem for public health. Among the main agents involved, cocaine stands out. It became one of the most abused drugs around the world, and one of the main reasons for visits to the emergency department due to the use of illicit substances. The use of cocaine is primarily in combination with alcoholic beverages. There are few studies that correlate cocaine blood concentration and the severity of clinical manifestations in patients evaluated at Emergency Department. The aim of the present study was to verify the possible relationship between the blood concentration of cocaine and cocaethylene (product of the interaction of cocaine with ethanol) with the severity of the clinical manifestations presented by patients with cocaine intoxication.

METHODS

Blood levels were measured by high-performance liquid chromatography (HPLC) and the severity of clinical manifestations was assessed using the Stimulant Intoxication Score (SIS). To establish this relationship, Pearson's chi-square statistical test (x²) was used for categorical variables and Student's t for continuous variables, with statistical significance of 5% (p < 0.05).

RESULTS

Of the 81 patients included in the study, 77.8% were men with a mean age of 32.5 years ± 8.5 and mean of SIS 3.4 ± 2.5. Considering the toxicological analysis results, 24.7% of the blood samples were positive. The mean of cocaine and cocaethylene concentrations were 0.34 μg/mL ± 0.45 and 0.38 μg/mL ± 0.34, respectively. The blood concentration of cocaine and cocaethylene has not been shown to be useful information for the treatment and prognosis of patients, but blood levels of these substances at the time of treatment, regardless of their concentration, may be an indicator of severity, showing that any concentrations of these substances should be considered as potentially toxic.

CONCLUSION

The application of the SIS score proved to be an important alternative capable of predicting the severity of the patients due to cocaine intoxication in a fast and simplified way.

Lipid emulsions in the treatment of intoxications by local anesthesics and other drugs. Review of mechanisms of action and recommendations for use

Intravenous lipid emulsions (ILEs) have been used widely for the treatment of local anesthetic (LA) poisoning and have been proposed as a treatment for intoxication by other drugs. However, the degree of evidence for this kind of therapy is not strong, as it comes mostly from clinical cases. The aim of this narrative review is to describe the proposed mechanisms of action for ILEs in poisoning by LA and other drugs and to evaluate recent studies in animals that support the recommendations for their use and the experience in humans that support the use of ILESs in both LA and other drug poisoning. For this purpose, a search was performed in the Embase, Medline and Google Scholar databases covering relevant articles over the last 10 years. In the case of AL poisoning, we recommend applying the protocols dictated by international guidelines, knowing that the degree of evidence is not very high. In poisoning by other drugs, ILEs are recommended in serious situations induced by liposoluble xenobiotics that do not respond to standard treatment.

Heterogeneity and bias in animal models of lipid emulsion therapy: a systematic review and meta-analysis

INTRODUCTION

Clinicians utilize lipid emulsion to treat local anesthetic toxicity and non-local anesthetic toxicities, a practice supported by animal experimentation and clinical experience. Prior meta-analysis confirmed a mortality benefit of lipid emulsion in animal models of local anesthetic toxicity but the benefit of lipid emulsion in models of non-local anesthetic toxicity remains unanswered. Further, swine suffer an anaphylactoid reaction from lipid emulsions calling into question their role as a model system to study lipid, so we examined swine and non-swine dependent outcomes in models of intravenous lipid emulsion.

METHODS

We conducted a systematic review and meta-analysis examining the use of lipid emulsion therapy in animal models of cardiac toxicity. We quantified mortality using a random-effects odds-ratio method. Secondary outcomes included survival in the following subgroups: local-anesthetic systemic toxicity, non-local anesthetic toxicity, swine-based models, and non-swine models (e.g., rat, rabbit and dog). We assessed for heterogeneity with Cochran's Q and I². We examined bias with Egger's test & funnel plot analysis.

RESULTS

Of 2784 references screened, 58 met criteria for inclusion. Treatment with lipid emulsion reduced chance of death in all models of toxicity with an odds ratio of death of 0.26 (95% CI 0.16-0.44, Z-5.21, p < 0.00001, Cohen's-d = 0.72, n = 60). Secondary outcomes confirmed a reduced chance of death in models of local anesthetic toxicity (OR 0.16 {95% CI 0.1-0.33}) and non-local anesthetic toxicity (OR 0.43 {95% CI 0.22-0.83}). Heterogeneity (Cochran's Q 132 {df = 59, p < 0.01}, I ² = 0.55) arose primarily from animal-model and disappeared (I ² < = 0.12) when we analyzed swine and non-swine subgroups independently. Swine only benefited in models of local anesthetic toxicity (OR 0.28 {95% CI 0.11-0.7}, p = 0.0033) whereas non-swine models experienced a homogeneous benefit across all toxins (OR 0.1 {95% CI 0.06-0.16}, p < 0.00001). Egger's test identified risk of bias with outliers on funnel plot analysis.

DISCUSSION

Lipid emulsion therapy reduces mortality in animal models of toxicity. Heterogeneity arises from the animal-model used. Swine only benefit in models of local anesthetic toxicity, potentially due to lipid dose, experimental design or swine's anaphylactoid reaction to lipid. Outlier analysis reinforced the need for appropriate dosing of lipid emulsion along with airway management and chest compressions in the setting of cardiac arrest.

Intravenous lipid emulsion to treat suspected cocaine toxicosis in a dog

A 6-month-old puppy was treated for suspected cocaine toxicosis. Supportive care was initiated but clinical signs worsened and treatment with intravenous lipid emulsion (ILE) was instituted. Clinical signs rapidly resolved in response to treatment with ILE.

Effect of Intravenous Lipid Emulsion on Clozapine Acute Toxicity in Rats

Objectives

Many studies have been reported the efficacy of intravenous lipid emulsion (ILE) as an antidote on acute lipophilic drug toxicity. Clozapine, highly lipophilic dibenzodiazepine neuroleptics, is an important medication in the schizophrenia therapy regimen. Acute intoxication with antipsychotics is one of the main reasons for the referral of poisoned patients to the hospital. We expected that ILE could be used for the therapy of acute clozapine intoxicated patients.

Methods

We used two groups of consisting of six male rats. Both groups received a toxic dose of clozapine (40 mg/kg) intravenously, via the tail vein. After 15 minutes, they were treated with intravenous infusion of 18.6 mg/kg normal saline (NS group), or 18.6 mg/kg ILE 20% (ILE group). We evaluated blood pressure (BP) and heart rate by power lab apparatus through the tail artery, ataxia by a rat rotary circle, seizure scores and death in multiple times after starting clozapine administration. For biochemical and pathological evaluations the samples of tissue and blood were taken.

Results

Our results demonstrated that ILE 20% could return hypotension-induced clozapine better than normal saline. Furthermore, ataxia and seizure have rectified more rapidly and deaths reduced. Clozapine administration causes pancreatitis and lung injury but fat emulsion did not show an optimal effect on tissue damages caused by clozapine toxicity.

Conclusion

In conclusion, ILE can remove toxic signs of clozapine same as other lipophilic medicines, however, clinical uses of ILE for this intention requires more appraisement to determine the precise implication and safety.

Successful intralipid-emulsion treatment of local anesthetic systemic toxicity following ultrasound-guided brachial plexus block: case report

Background

Local anesthetic systemic toxicity (LAST) is a life-threatening complication that may follow application of LAs through various routes. Despite increasing usage of LA techniques in a large number of health-care settings, contemporary awareness of LAST and understanding of its management are inadequate.

Case presentation

We report two cases who suffered LAST following brachial plexus block for surgery on the upper extremity. The first patient received an ultrasound-guided supraclavicular block with 300 mg lidocaine (6 mg/kg) and 50 mg ropivacaine (1 mg/kg) in 25 mL without epinephrine, and the second patient received an ultrasound guided interscalene block with 200 mg lidocaine (4.5 mg/kg) and 45 mg ropivacaine (1 mg/kg) supplemented with epinephrine 1:200,000. Both patients presented with symptoms of central nervous and respiratory system depression, the first roughly 10 minutes after injection, and the second immediately after withdrawal of the needle. In both cases, thorough recovery was obtained using lipid-emulsion therapy.

Conclusion

The complication of LAST following ultrasound-guided brachial plexus block could be treated successfully applying the American Society of Regional Anesthesia and Pain Medicineprotocol of intravenous administration of lipid emulsion.

The Mechanisms Underlying Lipid Resuscitation Therapy

The experimental use of lipid emulsion for local anesthetic toxicity was originally identified in 1998. It was then translated to clinical practice in 2006 and expanded to drugs other than local anesthetics in 2008. Our understanding of lipid resuscitation therapy has progressed considerably since the previous update from the American Society of Regional Anesthesia and Pain Medicine, and the scientific evidence has coalesced around specific discrete mechanisms. Intravenous lipid emulsion therapy provides a multimodal resuscitation benefit that includes both scavenging (eg, the lipid shuttle) and nonscavenging components. The intravascular lipid compartment scavenges drug from organs susceptible to toxicity and accelerates redistribution to organs where drug (eg, bupivacaine) is stored, detoxified, and later excreted. In addition, lipid exerts nonscavenging effects that include postconditioning (via activation of prosurvival kinases) along with cardiotonic and vasoconstrictive benefits. These effects protect tissue from ischemic damage and increase tissue perfusion during recovery from toxicity. Other mechanisms have diminished in favor based on lack of evidence; these include direct effects on channel currents (eg, calcium) and mass-effect overpowering a block in mitochondrial metabolism. In this narrative review, we discuss these proposed mechanisms and address questions left to answer in the field. Further work is needed, but the field has made considerable strides towards understanding the mechanisms.

Prevalence of cocaine and derivatives in blood and urine samples of trauma patients and correlation with injury severity: a prospective observational study

PURPOSE

The abuse of cocaine and its derivatives presents a likely risk factor for injury. Trauma incurred by cocaine and derivative abusers may be more severe than that incurred by non-users.

OBJECTIVES

To ascertain the presence of cocaine and its derivatives in trauma patients and to correlate RTS (Revised Trauma Score) and ISS (Injury Severity Score) with the presence of cocaine and its derivatives in blood and urine samples.

METHODS

All trauma victims treated in an emergency unit between November 11, 2012 and September 15, 2013 were included in the study. Blood and urine samples were collected on admission to hospital. RTS and ISS scores were then compared with the presence or absence of cocaine and its derivatives in the samples. The associations between RTS < 7.84 and ISS > 16 and the independent variables were evaluated by the gross odds ratio values, determined by univariate logistic regression. Multivariate analysis was performed using multivariate logistic regression.

RESULTS

Of 453 patients (83.7% male) included in the study, 28.6% presented ISS > 16 and 33.6% presented RTS < 7.84. A total of 435 samples were collected, and 86 (19.8%) provided positive samples for cocaine, 48 (11%) for crack and 69 (15.9%) for cocaethylene. Compared to other patients, drug users showed a greater probability of RTS < 7.84 (2.18 times greater) and a greater probability of ISS > 16 (1.76 times greater).

CONCLUSION

For the trauma patients included in our study, the use of cocaine and its derivatives was shown to be associated with more severe traumas, as demonstrated by their RTS and ISS scores.

Insulin Signaling in Bupivacaine-induced Cardiac Toxicity: Sensitization during Recovery and Potentiation by Lipid Emulsion

BACKGROUND

The impact of local anesthetics on the regulation of glucose homeostasis by protein kinase B (Akt) and 5'-adenosine monophosphate-activated protein kinase (AMPK) is unclear but important because of the implications for both local anesthetic toxicity and its reversal by IV lipid emulsion (ILE).

METHODS

Sprague-Dawley rats received 10 mg/kg bupivacaine over 20 s followed by nothing or 10 ml/kg ILE (or ILE without bupivacaine). At key time points, heart and kidney were excised. Glycogen content and phosphorylation levels of Akt, p70 s6 kinase, s6, insulin receptor substrate-1, glycogen synthase kinase-3β, AMPK, acetyl-CoA carboxylase, and tuberous sclerosis 2 were quantified. Three animals received Wortmannin to irreversibly inhibit phosphoinositide-3-kinase (Pi3k) signaling. Isolated heart studies were conducted with bupivacaine and LY294002-a reversible Pi3K inhibitor.

RESULTS

Bupivacaine cardiotoxicity rapidly dephosphorylated Akt at S473 to 63 ± 5% of baseline and phosphorylated AMPK to 151 ± 19%. AMPK activation inhibited targets downstream of mammalian target of rapamycin complex 1 via tuberous sclerosis 2. Feedback dephosphorylation of IRS1 to 31 ± 8% of baseline sensitized Akt signaling in hearts resulting in hyperphosphorylation of Akt at T308 and glycogen synthase kinase-3β to 390 ± 64% and 293 ± 50% of baseline, respectively. Glycogen accumulated to 142 ± 7% of baseline. Irreversible inhibition of Pi3k upstream of Akt exacerbated bupivacaine cardiotoxicity, whereas pretreating with a reversible inhibitor delayed the onset of toxicity. ILE rapidly phosphorylated Akt at S473 and T308 to 150 ± 23% and 167 ± 10% of baseline, respectively, but did not interfere with AMPK or targets of mammalian target of rapamycin complex 1.

CONCLUSION

Glucose handling by Akt and AMPK is integral to recovery from bupivacaine cardiotoxicity and modulation of these pathways by ILE contributes to lipid resuscitation.