Antidote Use in the Critically Ill Poisoned Patient

Clinical and demographic features with outcome predictors of adult patients with acute intoxication admitted to a medical intensive care unit in the Mediterranean part of Croatia

Background

The objective of the study was to assess the demographics, clinical parameters, and outcome of acute intoxications among adult patients admitted to a medical intensive care unit in southern Croatia.

Materials and Methods

An observational retrospective study was conducted over a 1-year period. The subjects were patients admitted to the intensive care unit for acute poisoning.

Results

In all, 81 subjects (32.1% females) aged 43.16 ± 14.77 years were admitted to the intensive care unit because of poisoning (14.97% of the total annual intensive care unit admissions). Psychiatric disorders were previously established in 76.5% participants, and 69.1% of all acute intoxications were classified as suicidal. Non-suicidal subjects differed from suicidal subjects in age (37.36 ± 9.71 vs. 45.75 ± 15.93 years; P = 0.009), in pCO2 (6.38 ± 1.78 vs. 5.50 ± 1.26 kPa; P = 0.020), in length-of-stay in intensive care unit (median 1.00, interquartile range 1.00 vs. median 2.00, interquartile range 2.00 days; P = 0.022), and in length-of-stay in hospital (median 2.00, interquartile range 2.00 vs. median 10.50, interquartile range 15.25 days; P < 0.001). Three (3.7%) patients died. Pharmaceutical psychoactive drug intoxications were the most common poisoning cases; of these, diazepam was the most frequent (16.8%), followed by ethanol (9.0%) and alprazolam (7.8%). Benzodiazepines/hypnotics were the most common group (28.7%), followed by antipsychotics (13.2%). Intoxications with more than 1 poison accounted for the largest number of cases (67.9%). The number of toxins was significantly correlated with length-of-stay in the hospital (rho = -0.265; P = 0.008), systolic blood pressure (rho = -0.318; P = 0.002), and diastolic blood pressure (rho = -0.262; P = 0.009). The electrocardiogram was considered abnormal in 50.62% of the cases.

Conclusion

Acute intoxicants were most commonly caused by psychiatric pharmaceutical drugs. Multidrug exposure was a typical pattern of acute intoxication.

Evaluation of protective effects of methylene blue on cisplatin-induced nephrotoxicity

Cisplatin (CP) is used to treat various types of cancer. However, its usage is limited due to nephrotoxicity. This study aims to examine the applicability of methylene blue (MB) against CP-induced kidney injuries. In this study, twenty-eight male rats were divided into four groups. Following administration of a single dose of CP (5 mg/kg), animals received intraperitoneal injections (IP) of MB (4 mg/kg) for seven days. In the final phase of the experiment, serum was collected from rats, with blood urea nitrogen (BUN) and creatinine (Cr) levels measured. Hematoxylin-Eosin (H&E) and Masson's trichrome staining were performed to examine histological changes. Immuno-histological staining was used to evaluate caspase-3 protein expression. The results showed that the MB (4 mg/kg) + CP treated rats underwent a lesser weight loss compared to the CP group (p < 0.05 and p < 0.001, respectively). The kidney weight decreased significantly in the CP + MB group compared to the CP group (p < 0.05 and p < 001, respectively). BUN and Cr levels that were increased significantly in the serum of the CP group (p < 0.001) compared to the control group showed no significant increase in the MB + CP group compared to the control group (p = 0.842 and p = 0.989, respectively). There was a significant decrease in kidney tissue injuries in the CP + MB compared to the CP group (p < 0.001). The glomerular size was recovered in the CP + MB group compared to the CP (p < 0.05). The significant increase in the capsular space of the CP group compared to the control group (p < 0.001) was attenuated in the CP + MB. MB restored the histological alterations in the kidneys. Treatment with 4 mg/kg of MB reduced the expression levels of Caspase-3. In conclusion, this study provides evidence concerning the anti-apoptotic roles of MB in CP-induced kidney damage. In conclusion, MB has a positive impact on kidney function.

Fatal overdose of Taxus baccata plant matter treated in a rural district general hospital

A 25-year-old woman presented with cardiogenic shock following intentional overdose of Common Yew (Taxus baccata). The pharmacological mechanisms underlying yew toxicity resulted in failure of multiple treatment modalities including inotropes, vasopressors and attempted pacing. Resuscitation was ultimately unsuccessful. The limited literature available on this kind of overdose suggests that early extracorporeal membrane oxygenation (ECMO) is the mainstay of treatment in severe cases presenting with hypotension and arrhythmias. However, there may be a role for digoxin antibody fragments in maintaining patients presenting to remote sites, to allow transfer to a specialist centre.

Availability of Essential Antidotes and the Role of Community Pharmacists in the Management of Acute Poisoning: A Cross-Sectional Study in Ethiopia

Background

Morbidity and mortality related to acute poisoning is a major public health issue in both developing and developed countries. Community pharmacists have a crucial role in ensuring drug availability, increasing drug safety, counseling patients, overdose risk reduction and management, and provision of appropriate drug information. This study aimed to assess the availability of necessary antidotes in community pharmacies in Gondar and Bahir-Dar cities, Ethiopia, and the role of community pharmacists in the management of acute poisoning.

Methods

A cross-sectional survey was conducted in Gondar and Bahir-Dar cities. A self-administered, structured questionnaire was used for data collection and Statistical Package for Social Sciences (SPSS) version 24.0 was used for data analysis. Chi-square analysis was computed to identify the associated factors with a confidence interval of 95% and a P value less than .05 was used as a cut-point for statistical significance.

Results

Out of 101 community pharmacies invited to participate in the study, 80 of them completed the survey with a response rate of 79.2%. The overall mean antidote availability score was .59 (SD = .837), which falls within the definition of Poor availability. None of the pharmacies had kept all of the antidotes, and the maximum number of an antidote kept by a single pharmacy was 7 out of nineteen essential antidotes surveyed. The most commonly reported reason for the unavailability of essential antidotes was stock was not ordered (56.3%) followed by stock ordered but not delivered from suppliers (wholesalers) (20.0%). More than 3 fourth of the respondents (83.8%) had poor knowledge about the antidotes for the common poisonings.

Conclusion

There was a significantly very low availability of essential antidotes in the community pharmacies. Strategies should be implemented to improve pharmacist’s knowledge about antidotes, and management of poisoning emergencies through on-job training and provision of reference materials.

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

Antidotes for childhood toxidromes

Background

Poisoning causes significant morbidity and sometimes mortality in children worldwide. The clinical skill of toxidrome recognition followed by the timely administration of an antidote specific for the poison is essential for the management of children with suspected poisoning. This is a narrative review on antidotes for toxidromes in paediatric practice.

Methods

A literature search was conducted on PubMed with the keywords “antidote”, “poisoning”, “intoxication”, “children” and “pediatric”. The search was customized by applying the appropriate filters (species: humans; age: birth to 18 years) to obtain the most relevant articles for this review article.

Results

Toxidrome recognition may offer a rapid guide to possible toxicology diagnosis such that the specific antidote can be administered in a timely manner. This article summarizes toxidromes and their respective antidotes in paediatric poisoning, with an emphasis on the symptomatology and source of exposure. The antidote and specific management for each toxidrome are discussed. Antidotes are only available for a limited number of poisons responsible for intoxication. Antidotes for common poisonings include N-acetyl cysteine for paracetamol and sodium thiosulphate for poisoning by cyanide.

Conclusion

Poisoning is a common cause of paediatric injury. Physicians should be familiar with the recognition of common toxidromes and promptly use specific antidotes for the management of childhood toxidromes.

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

Recent Bio-Advances in Metal-Organic Frameworks

Metal-organic frameworks (MOFs) have found uses in adsorption, catalysis, gas storage and other industrial applications. Metal Biomolecule Frameworks (bioMOFs) represent an overlap between inorganic, material and medicinal sciences, utilising the porous frameworks for biologically relevant purposes. This review details advances in bioMOFs, looking at the synthesis, properties and applications of both bioinspired materials and MOFs used for bioapplications, such as drug delivery, imaging and catalysis, with a focus on examples from the last five years.

Fundaments of Toxicology-Approach to the Poisoned Patient

Management of the poisoned patient begins with supportive care, assessment of organ function and dysfunction, and consideration of known or suspected poisons. The possibility of multiple ingestions should be considered with intentional exposures or suicide attempts. Enteric decontamination involves treatment to prevent the absorption of toxins from the gastrointestinal system and includes the use of activated charcoal. Poisoned patients may benefit from the use if antidotes are available, or enhanced elimination as with salicylate ion trapping during urinary alkalinization. The use of intravenous lipid therapy is of clinical benefit in poisoning from bupivacaine, amitriptyline, and bupropion. Hemodialysis is the most inexpensive, widely available, and most commonly used method of extracorporeal drug removal in the treatment of poisoning. Chelators with different chemical properties can bind toxic metals, providing an essential mechanism for detoxification, and may be used in combination with extracorporeal therapies such as DFO with HD for aluminum or iron, and DMSA or DMPS with HD to treat arsenic or mercury intoxication. The use of displacers with hemodialysis can be considered to augment clearance of protein-bound toxins.

Therapeutic effects of physostigmine during systemic inflammation

Introduction

Usually, physostigmine is used as antidote for anticholinergic poisons in order to improve hemodynamics and cardiac output. In addition, it causes beneficial effects during sepsis when added timely. Here, we studied whether physostigmine improves hemodynamics when treatment during systemic inflammation was delayed.

Methods

Two series of randomized studies with overall 44 rats were conducted. Systemic inflammation was induced by lipopolysaccharide (LPS) infusion (0.5 mg LPS/kg×h). Physostigmine (PHY) was intravenously applied after an LPS infusion period of 90 minutes (50 µg PHY/kg within 10 minutes) with (series 1) and without (series 2) additional volume loading. Hemodynamic parameters, blood gases, and parameters for tissue damage were periodically determined for up to 180 minutes.

Results

Even though volume was additionally administered (series 1), LPS caused a reduction of peripheral blood flow. Treatment with PHY improved hemodynamics in macrocirculation (mean arterial blood pressure) and microcirculation (peripheral blood flow). PHY neither affected alterations in blood gases, electrolyte homeostasis, and glucose metabolism nor prevented intestinal damage induced by LPS. In series 2, without any additional volume loading, PHY likewise resulted in an improvement of the LPS-induced alterations in macro- and microcirculation, but finally worsened the LPS-mediated effects on plasma parameters for tissue damage such as creatine kinase, probably due to the lack of volume and a further damage to the heart.

Conclusion

The present results demonstrated that hemodynamic responses to PHY may not only be visible in patients with anticholinergic drug overdose but also be visible in septic patients, provided that fluid intake of these patients is adequate.

Poisoning cases and their management in emergency centres of government hospitals in northwest Ethiopia

Introduction

With the widespread availability of a vast number of chemicals and drugs, acute poisoning is a common medical emergency worldwide. In spite of the success of interventions to prevent toxic ingestions, acute poisoning continues to be an important public health problem. Because of weak regulations and limited health care services in developing countries, adverse outcomes from poisoning are more prevalent than in the developed world. Due to the limited Ethiopian literature on this topic, the primary objective of this study was to evaluate and report poisoning cases, their management and outcome in northwest Ethiopia.

Methods

This is a retrospective study of all poisoning cases admitted and managed in the emergency centres of Gondar Teaching Referral Hospital and Metema and Debark district hospitals, from September 2010 to December 2014. Data was collected through retrospective chart review of patients who were admitted due to poisoning.

Results

There were 543 registered poisoning cases listed in the registry during the study period, of which 344 cases (63.4%) had complete data and were included in the final analysis. There were 48,619 emergency centre visits during the study period, with poisoning cases accounting for 1.1%. Females (60%) were predominant among intentional as well as unintentional poisoning cases. Patients between 15 and 24 years of age accounted for 55% of the cases. Patients poisoned with organophosphate and bleaching agents accounted for 35% and 25%, respectively. Among the poisoning patients, 74% were treated with decontamination, while those exposed to organophosphate were treated with atropine 45.5% (55/121) of the time.

Discussion

Young females comprise a group at increased risk for suicidal poisonings. As a developing nation, pesticide and bleaching agents remain a significant cause of acute poisonings in Ethiopia. Intentional poisoning remains the most significant identified cause of poisoning overall.

Structural perturbation of a dipalmitoylphosphatidylcholine (DPPC) bilayer by warfarin and its bolaamphiphilic analogue: A molecular dynamics study

Compounds with nominally similar biological activity may exhibit differential toxicity due to differences in their interactions with cell membranes. Many pharmaceutical compounds are amphiphilic and can be taken up by phospholipid bilayers, interacting strongly with the lipid-aqueous interface whether or not subsequent permeation through the bilayer is possible. Bolaamphiphilic compounds, which possess two hydrophilic ends and a hydrophobic linker, can likewise undergo spontaneous uptake by bilayers. While membrane-spanning bolaamphiphiles can stabilize membranes, small molecules with this characteristic have the potential to create membrane defects via disruption of bilayer structure and dynamics. When compared to the amphiphilic therapeutic anticoagulant, warfarin, the bolaamphiphilic analogue, brodifacoum, exhibits heightened toxicity that goes beyond superior inhibition of the pharmacological target enzyme. We explore, herein, the consequences of anticoagulant accumulation in a dipalmitoylphosphatidylcholine (DPPC) bilayer. Coarse-grained molecular dynamics simulations reveal that permeation of phospholipid bilayers by brodifacoum causes a disruption of membrane barrier function that is driven by the bolaamphiphilic nature and size of this molecule. We find that brodifacoum partitioning into bilayers causes membrane thinning and permeabilization and promotes lipid flip-flop - phenomena that are suspected to play a role in triggering cell death. These phenomena are either absent or less pronounced in the case of the less toxic, amphiphilic compound, warfarin.

Initial evaluation and management of the critical burn patient

The major improvement in burn therapy is likely to focus on the early management of hemodynamic and respiratory failures in combination with an aggressive and early surgical excision and skin grafting for full-thickness burns. Immediate burn care by first care providers is important and can vastly alter outcomes, and it can significantly limit burn progression and depth. The goal of prehospital care should be to cease the burning process as well as prevent future complications and secondary injuries for burn shock. Identifying burn patients appropriate for immediate or subacute transfer is an important step in reducing morbidity and mortality. Delays in transport to Burn Unit should be minimized. The emergency management follows the principles of the Advanced Trauma Life Support Guidelines for assessment and stabilization of airway, breathing, circulation, disability, exposure and environment control. All patients with suspected inhalation injury must be removed from the enclosure as soon as possible, and immediately administer high-flow oxygen. Any patient with stridor, shortness of breath, facial burns, singed nasal hairs, cough, soot in the oral cavity, and history of being in a fire in an enclosed space should be strongly considered for early intubation. Fibroscopy may also be useful if airway damage is suspected and to assess known lung damage. Secondary evaluation following admission to the Burn Unit of a burned patient suffering a severe thermal injury includes continuation of respiratory support and management and treatment of inhalation injury, fluid resuscitation and cardiovascular stabilization, pain control and management of burn wound.

Methylene blue rescues heart defects in a Drosophila model of Friedreich's ataxia

Friedreich's ataxia (FRDA), the most common hereditary ataxia, is characterized by progressive degeneration of the central and peripheral nervous system, hypertrophic cardiomyopathy and a high risk of diabetes. FRDA is caused by abnormally low levels of frataxin, a highly conserved mitochondrial protein. Drosophila has been previously successfully used to model FRDA in various cell types, including neurons and glial cells. Here, we report the development of a Drosophila cardiac model of FRDA. In vivo heart imaging revealed profound impairments in heart function in frataxin-depleted Drosophila, including a strong increase in end-systolic and end-diastolic diameters and a decrease in fractional shortening (FS). These features, reminiscent of pathological phenotypes in humans, are fully rescued by complementation with human frataxin, suggesting conserved cardiac functions of frataxin between the two organisms. Oxidative stress is not a major factor of heart impairment in frataxin-depleted flies, suggesting the involvement of other pathological mechanisms notably mitochondrial respiratory chain (MRC) dysfunction. Accordingly, we report that methylene blue (MB), a compound known to act as an alternative electron carrier that bypasses mitochondrial complexes I-III, was able to prevent heart dysfunction. MB also partially rescued the phenotype when administered post-symptomatically. Analysis of MB derivatives demonstrates that only compounds with electron carrier properties are able to prevent the heart phenotype. Thus MB, a compound already used for several clinical applications, appears promising for the treatment of the heart dysfunctions that are a major cause of death of FRDA patients. This work provides the grounds for further evaluation of MB action in mammals.

Effects of ionic strength on the antimicrobial photodynamic efficiency of methylene blue

Antimicrobial photodynamic therapy (APDT) may become a useful clinical tool to treat microbial infections, and methylene blue (MB) is a well-known photosensitizer constantly employed in APDT studies, and although MB presents good efficiency in antimicrobial studies, some of the MB photochemical characteristics still have to be evaluated in terms of APDT. This work aimed to evaluate the role of MB solvent's ionic strength regarding dimerization, photochemistry, and photodynamic antimicrobial efficiency. Microbiological survival fraction assays on Escherichia coli were employed to verify the solution's influence on MB antimicrobial activity. MB was evaluated in deionized water and 0.9% saline solution through optical absorption spectroscopy; the solutions were also analysed via dissolved oxygen availability and reactive oxygen species (ROS) production. Our results show that bacterial reduction was increased in deionized water. Also we demonstrated that saline solution presents less oxygen availability than water, the dimer/monomer ratio for MB in saline is smaller than in water and MB presented a higher production of ROS in water than in 0.9% saline. Together, our results indicate the importance of the ionic strength in the photodynamic effectiveness and point out that this variable must be taken into account to design antimicrobial studies and to evaluate similar studies that might present conflicting results.

Dye-enhanced multimodal confocal imaging as a novel approach to intraoperative diagnosis of brain tumors

Intraoperative diagnosis plays an important role in accurate sampling of brain tumors, limiting the number of biopsies required and improving the distinction between brain and tumor. The goal of this study was to evaluate dye-enhanced multimodal confocal imaging for discriminating gliomas from nonglial brain tumors and from normal brain tissue for diagnostic use. We investigated a total of 37 samples including glioma (13), meningioma (7), metastatic tumors (9) and normal brain removed for nontumoral indications (8). Tissue was stained in 0.05 mg/mL aqueous solution of methylene blue (MB) for 2-5 minutes and multimodal confocal images were acquired using a custom-built microscope. After imaging, tissue was formalin fixed and paraffin embedded for standard neuropathologic evaluation. Thirteen pathologists provided diagnoses based on the multimodal confocal images. The investigated tumor types exhibited distinctive and complimentary characteristics in both the reflectance and fluorescence responses. Images showed distinct morphological features similar to standard histology. Pathologists were able to distinguish gliomas from normal brain tissue and nonglial brain tumors, and to render diagnoses from the images in a manner comparable to haematoxylin and eosin (H&E) slides. These results confirm the feasibility of multimodal confocal imaging for intravital intraoperative diagnosis.

[Antidotes: use guidelines and minimun stock in an emergency department]

OBJECTIVE

To develop a guide for antidotes and other medications used to counteract poisoning, and define the stock in an emergency department, as a safety priority for the part-time pharmacist assigned to the unit.

METHOD

A search of specialist databases and web portals of the Spanish Society of Toxicology and the British National Poisons Information Service, as well as toxicology databases, TOXICONET, information from other hospitals, tertiary sources, Micromedex and Medline.

RESULTS

The Guide contains 42 active ingredients and is accessible to the Pharmacy and Emergency departments in electronic format. A minimum emergency stock was agreed based on the daily treatment of a 100 kg patient. This information, including updated expiry dates, is available at the emergency department antidote stock facilities and in electronic format. On a monthly basis, the pharmacist reviews the need to replace any drugs, due to their expiry date or lack of use.

DISCUSSION

The lack of evidence from high quality antidote studies, the variability due to the difficulties of updating sources and some geographical differences in their use means that decision-making can be difficult. It would be useful to have minimum quantity recommendations from societies of toxicology, regulatory agencies and organisations such as the Joint Commission on the Accreditation of Healthcare Organisations. It would also be useful to have a suprahospital risk assessment to optimise management and ensure the availability of antidotes which are expensive, have a limited shelf life, or of which demand is difficult to forecast.

Structure-based development of bacterial nitroreductase against nitrobenzodiazepine-induced hypnosis

Nitrobenzodiazepine (NBDZ) is an addictive drug of the abused substances that causes severe neurological effects and even death. Bacterial type I nitroreductase NfsB (EC 1.5.1.34) has been reported to catalyze NBDZ into inactive metabolite 7-amino-benzodiazepine (7ABDZ) with promising activity, so as to become an attractive candidate for treatment of NBDZ overdose and addiction. Here, we investigate the nitroreduction of an NBDZ, flunitrazepam (FZ), by various mutants of NfsB designed from the solved crystal structure and characterize their in vitro and in vivo potency. Conformational changes occurred in the active site of N71S/F124W in contrast to the wild-type, including the flipping on the aromatic rings of W124 and F70 as well as the extension on the hydrogen bond network between flavin mononucleotide (FMN) and S71, which allow the significant enlargement in the active site pocket. In the complex structure of N71S/F124W and nicotinamide (NIA), stacking sandwich attractions of W124-FMN-NIA were also found, implying the importance of W124 in substrate accessibility. Consequently, N71S/F124W exhibited increased 7AFZ production in vitro with nearly no toxicity and reduced 50% sleeping time (hypnosis) in vivo. Taken together, we demonstrate for the first time that N71S/F124W can serve as an effective antidote for NBDZ-induced hypnosis and provide the molecular basis for designing NfsB and the like in the future.

Evaluate the impact of hospital types on the availability of antidotes for the management of acute toxic exposures and poisonings in Malaysia

INTRODUCTION

The availability of antidotes may be considered essential and lifesaving in the management of certain poisonings. Surveys carried out in a number of countries have demonstrated inadequate availability of a variety of poisoning antidotes.

OBJECTIVES

The purpose of this study was to determine the availability of antidote stocking at hospitals, based on published guidelines for antidote stocking, and to evaluate the impact of hospital types on the availability of antidotes for the management of acute toxic exposures and poisonings in Malaysia.

METHODS

A questionnaire on the availability of antidotes was sent to all government accident and emergency departments in Malaysia. The list of commonly required antidotes and essential drugs was compiled from published guidelines. Collected data were analysed in SPSS version 16 using descriptive and comparative analysis.

RESULTS

The response rate was 59.06%. None of the responding hospitals stocked all of the antidotes on the lists. In relation to hospital type, there was great variability in the availability of antidotes (there were significant differences between hospitals for 13 antidotes). The availabilities of most antidotes were far better in the General Hospitals and the District Hospitals with specialists compared to District Hospitals without specialists. Calcium gluconate, sodium bicarbonate, atropine sulphate, naloxone, flumazenil, vitamin K, and pyridoxine were available at all general hospitals. Atropine sulphate and naloxone were available at all district hospitals with specialists.

CONCLUSION

Most Malaysian government hospitals stocked some important antidotes. Raising awareness of the importance of antidotes by education, regular review of antidote storage, distribution plans, and appropriate legislation might provide solutions. Coordination between Malaysian hospitals and the National Poison Centre at Universiti Sains Malaysia is also important.

Development, validation, and application of a fast and simple GC-MS method for determination of some therapeutic drugs relevant in emergency toxicology

BACKGROUND

To date, immunoassays are commercially available for quantification of valproic acid, salicylic acid, paracetamol, phenobarbital, phenytoin, and primidone. As they are no longer available, a fast, simple, and cost-effective quantitative gas chromatography-mass spectrometry (GC-MS) method was developed and fully validated for these drugs.

METHODS

After simple and fast liquid-liquid extraction, the samples were analyzed by GC-MS using the selected ion monitoring mode. The method was validated including the parameters selectivity, calibration model, precision, accuracy, and extraction efficiency.

RESULTS

The above-mentioned analytes were separated within 8.5 minutes and sensitively detected. No interfering peaks were observed in blank samples from 8 different sources. The linearity ranges were 20-200 mg/L for valproic acid, 100-1200 mg/L for salicylic acid, 10-200 mg/L for paracetamol, 10-200 mg/L for phenobarbital, 4-20 mg/L for primidone, and 2.5-30 mg/L for phenytoin. Generally accepted criteria for accuracy and precision were fulfilled for all analytes using 6-point calibration. Even 1-point calibration was applicable for all analytes. The assay was successfully applied to analysis of real plasma samples and proficiency testing material.

CONCLUSIONS

The assay described allowed fast and reliable determination of analytes relevant in the diagnosis of poisonings. Furthermore, time- and cost-saving 1-point calibration was shown to be suitable for daily routine work, especially in emergency cases.

Nanodetoxification: emerging role of nanomaterials in drug intoxication treatment

Treatment for intoxication involves the neutralization or clearance of a toxic compound, but the current methods of treatment are limited in their ability to safely and effectively detoxify the patient. Emerging research has focused on using nanoparticles as parenteral detoxifying agents to circulate through the body and capture toxins. The variable compositions of these nanoparticles control the mechanism in which they capture and remove specific compounds. As discussed in this article, the recent methods for utilizing nanoparticles for detoxification show great potential for intoxication treatment. However, several challenges must be overcome before a universal nanoparticle detoxification method is available for clinical use.

Toxicology today: what you need to know now

Clinicians are frequently confronted with toxicological emergencies and challenged with the task of correctly identifying the possible agents involved and providing appropriate treatments. In this review article, we describe the epidemiology of overdoses, provide a practical approach to the recognition and diagnosis of classic toxidromes, and discuss the initial management strategies that should be considered in all overdoses. In addition, we evaluate some of the most common agents involved in poisonings and present their respective treatments. Recognition of toxidromes with knowledge of indications for antidotes and their limitations for treating overdoses is crucial for the acute care of poisoned patients.

Therapeutic approaches to delay the onset of Alzheimer's disease

The key cytopathologies in the brains of Alzheimer's disease (AD) patients include mitochondrial dysfunction and energy hypometabolism, which are likely caused by the accumulation of small aggregates of amyloid-β (Aβ) peptides. Thus, targeting these two abnormalities of the AD brain may hold promising therapeutic value for delaying the onset of AD. In his paper, we discuss two potential approaches to delay the onset of AD. The first is the use of low dose of diaminophenothiazins (redox active agents) to prevent mitochondrial dysfunction and to attenuate energy hypometabolism. Diaminophenothiazines enhance mitochondrial metabolic activity and heme synthesis, both key factors in intermediary metabolism of the AD brain.The second is to use the naturally occurring osmolytes to prevent the formation of toxic forms of Aβ and prevent oxidative stress. Scientific evidence suggests that both approaches may change course of the basic mechanism of neurodegeneration in AD. Osmolytes are brain metabolites which accumulate in tissues at relatively high concentrations following stress conditions. Osmolytes enhance thermodynamic stability of proteins by stabilizing natively-folded protein conformation, thus preventing aggregation without perturbing other cellular processes. Osmolytes may inhibit the formation of Aβ oligomers in vivo, thus preventing the formation of soluble oligomers. The potential significance of combining diaminophenothiazins and osmolytes to treat AD is discussed.

Use of calcium folinate in the management of accidental methotrexate ingestion in two dogs

CASE DESCRIPTION

2 English Pointers were suspected of having consumed toxic doses of methotrexate, a dihydrofolate reductase inhibitor frequently used in human and veterinary chemotherapeutic protocols.

CLINICAL FINDINGS

Potentially toxic plasma concentrations of methotrexate were detected in both dogs. Results of physical examination, a CBC, blood gas analysis, and serum biochemical analysis were predominantly unremarkable, although 1 dog had mild hyponatremia (1372 mmol/L; reference range, 140 to 153 mmol/L) and mild hypocalcemia (1.03 mmol of ionized calcium/L; reference range, 1.13 to 1.33 mmol of ionized calcium/L).

TREATMENT AND OUTCOME

Point-of-care determination of plasma methotrexate concentrations was not available; thus, palliative care was provided. Emesis was induced in both dogs by SC administration of apomorphine, and 3 doses of a suspension of activated charcoal with sorbitol were administered orally over a 6-hour period. Fluid diuresis was initiated in both dogs by administration of a compound sodium lactate solution, and N-acetylcysteine was administered IV to both dogs as a hepatoprotectant. A solution of calcium folinate (also known as leucovorin) was administered IV to both dogs to mitigate the effects of ingested methotrexate. No adverse effects associated with calcium folinate administration were identified, and no clinical or pathological evidence of methotrexate intoxication was detected.

CLINICAL RELEVANCE

IV administration of calcium folinate appeared to prevent the pathological sequelae of methotrexate intoxication without adverse effects. Administration of calcium folinate is recommended for the treatment of dogs with suspected or confirmed methotrexate overdose.

Drug interactions at the blood-brain barrier: fact or fantasy?

There is considerable interest in the therapeutic and adverse outcomes of drug interactions at the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). These include altered efficacy of drugs used in the treatment of CNS disorders, such as AIDS dementia and malignant tumors, and enhanced neurotoxicity of drugs that normally penetrate poorly into the brain. BBB- and BCSFB-mediated interactions are possible because these interfaces are not only passive anatomical barriers, but are also dynamic in that they express a variety of influx and efflux transporters and drug metabolizing enzymes. Based on studies in rodents, it has been widely postulated that efflux transporters play an important role at the human BBB in terms of drug delivery. Furthermore, it is assumed that chemical inhibition of transporters or their genetic ablation in rodents is predictive of the magnitude of interaction to be expected at the human BBB. However, studies in humans challenge this well-established paradigm and claim that such drug interactions will be lesser in magnitude but yet may be clinically significant. This review focuses on current known mechanisms of drug interactions at the blood-brain and blood-CSF barriers and the potential impact of such interactions in humans. We also explore whether such drug interactions can be predicted from preclinical studies. Defining the mechanisms and the impact of drug-drug interactions at the BBB is important for improving efficacy of drugs used in the treatment of CNS disorders while minimizing their toxicity as well as minimizing neurotoxicity of non-CNS drugs.

Toxicology in the critical care unit

Toxicologic conditions are encountered in critically ill patients due to intentional or unintentional misuse of or exposure to therapeutic or illicit drugs. Additionally, toxicities related to medical interventions may develop in hospitalized patients. This review focuses on recent developments in the field of critical care toxicology. Early interventions to decrease absorption or enhance elimination of toxins have limited value. Specific interventions to manage toxicities due to analgesics, sedative-hypnotics, antidepressants, antipsychotics, cardiovascular agents, alcohols, carbon monoxide, and cholinergic agents are reviewed. Hospital-acquired toxicities due to methemoglobinemia, propylene glycol, and propofol should be recognized and treated. The clinician is continually required to incorporate clinical judgment along with available scientific data and clinical evidence to determine the best therapy for toxicologic conditions.