ABSTRACT
Paraquat®, or N,N'-dimethyl-4,4'-bipyridinium dichloride, is a bipyridyl compound used as a non-selective herbicide and desiccant that can cause acute poisoning through all routes of exposure. There is no known antidote, and the available treatments are based on avoiding its absorption and timely removing it, in adults and children. We describe a case series of 14 pediatric patients from the department of Cauca, Colombia, with acute intoxication after oral intake of paraquat. Patients were referred to a medium-high complexity hospital in southwestern Colombia and treated according to an institutional protocol for acute paraquat poisoning. Acute paraquat poisoning after oral ingestion is associated with a high mortality rate, even with timely medical attention, as the compound has no known antidote and quickly reaches systemic concentrations for fulminant poisoning. Based on the available literature, our center has proposed a clinical protocol including early standard management, immunosuppressive and antioxidant treatments, and systemic removal techniques. This protocol suggests an adequate approach to acute paraquat poisoning in the pediatric population.
El dicloruro de 1,1'-dimetil-4,4'-bipiridilo (Paraquat®) es un compuesto químico de la familia de las piridinas, utilizado como herbicida no selectivo y desecante. Este compuesto puede causar intoxicación aguda por todas las vías de exposición. En el momento, no hay un antídoto conocido y los tratamientos disponibles, incluidos los pediátricos, se basan en contrarrestar su absorción y propiciar su remoción oportuna. Se describe una serie de casos de 14 pacientes pediátricos, procedentes en su mayoría del departamento del Cauca, con intoxicación aguda por ingestión de paraquat. Los pacientes fueron remitidos y atendidos en un hospital de mediana a alta complejidad en el suroccidente colombiano, con un protocolo institucional para el manejo de la intoxicación aguda por el herbicida. La intoxicación aguda con paraquat por vía oral se asocia con una alta tasa de mortalidad, aún con atención médica oportuna, pues fácilmente se alcanzan concentraciones sistémicas para ser fulminante. Basado en la literatura disponible, el Hospital Universitario San José ha propuesto un protocolo clínico adecuado para la intoxicación aguda por paraquat en población pediátrica que incluye manejo estándar temprano, tratamiento inmunosupresor y antioxidante, y técnicas para su remoción sistémica.
Subject(s)
Algorithms , Herbicides , Paraquat , Humans , Paraquat/poisoning , Child , Female , Male , Child, Preschool , Adolescent , Herbicides/poisoning , Poisoning/therapy , Poisoning/drug therapy , Colombia , Acute Disease , Infant , Antioxidants/therapeutic use , Clinical Protocols , Antidotes/therapeutic useSubject(s)
Humans , Female , Middle Aged , Thyroxine/toxicity , Poisoning/drug therapy , Hemoperfusion , Ultrafiltration , Renal DialysisABSTRACT
BACKGROUND: The diagnosis of toxic alcohol poisoning is often based on clinical presentation and nonspecific surrogate laboratory studies due to limited testing availability. Fomepizole is the recommended antidote and often administered empirically. The objective of this study is to identify substances that mimic toxic alcohols and compare key clinical factors between toxic alcohol and non-toxic alcohol exposures when fomepizole was administered. METHODS: This study was a retrospective evaluation using the National Poison Data System from January 1, 2010 through December 31, 2021. Exposures were included if fomepizole was administered. Toxic alcohol exposures had ethylene glycol or methanol as a coded substance. For exposures not coded as a toxic alcohol, the first substance was described. Paracetamol (acetaminophen) exposures from 2020 and 2021 were excluded. RESULTS: Fomepizole was reportedly used 25,110 times over 12 years. Use increased from 1,955 in 2010 to 2,710 in 2021. Most administrations were for reported toxic alcohol poisoning (60 percent) but use in reported non-toxic alcohol poisoning was greater starting in 2020. Toxic alcohol exposures were older (43.3 versus 39.8 years; P < 0.001) and more likely male (65.7 percent versus 58.2 percent). Level of care was mostly a critical care unit (67.7 percent), which was less common in toxic alcohol (63.3 percent) than non-toxic alcohol exposures (74.2 percent). The most common non-toxic alcohol substances were ethanol (24.9 percent) or an unknown drug (17.5 percent). Acidosis, increased creatinine concentration, anion gap, and osmolal gap, and kidney failure were coded in a lower proportion of toxic alcohol exposures than non-toxic alcohol exposures (P < 0.001). DISCUSSION: The inability to provide rapid clinical confirmation of toxic alcohol poisoning results in the empiric administration of fomepizole to many patients who will ultimately have other diagnoses. Although fomepizole is relative well tolerated we estimated that this practice costs between $1.5 to $2.5 million. The major limitations of this work include the biases associated with retrospective record review, and the inability to confirm the exposures which may have resulted in allocation error. CONCLUSION: Most fomepizole use was for a presumed toxic alcohol. This recently shifted to greater use in likely non-toxic alcohol poisoning. Key difference between the groups suggest fomepizole administration was likely due to the difficulty in diagnosis of toxic alcohol poisoning along with the efficacy and safety of fomepizole. Increased toxic alcohol laboratory testing availability could improve timely diagnosis, reserving fomepizole use for toxic alcohol poisoning.
Subject(s)
Poisoning , Poisons , Humans , Male , United States/epidemiology , Fomepizole/therapeutic use , Poisons/therapeutic use , Retrospective Studies , Pyrazoles/therapeutic use , Pyrazoles/toxicity , Antidotes/therapeutic use , Ethanol , Methanol , Ethylene Glycol , Renal Dialysis/methods , Poisoning/diagnosis , Poisoning/epidemiology , Poisoning/drug therapyABSTRACT
OBJECTIVE: To discuss the clinical presentation and successful treatment of a suspected case of intermediate syndrome due to organophosphate (OP) poisoning in a dog. CASE SUMMARY: Two dogs presented with acute cholinergic signs after ingesting an OP insecticide containing 50% acephate. Clinical signs consistent with acute cholinergic crisis resolved in both dogs within 24 hours postingestion. One dog developed an onset of neurological signs consistent with intermediate syndrome approximately 24 hours postingestion. This patient's clinical signs resolved with the use of pralidoxime chloride. NEW OR UNIQUE INFORMATION PROVIDED: OP poisoning most commonly presents as an acute cholinergic crisis, with rare instances of animals developing intermediate syndrome. Few reports of successful treatment and recovery from intermediate syndrome exist in the veterinary literature, particularly with instances in which 2 dogs within the same exposure setting were treated for acute cholinergic signs and only 1 progressed to an intermediate syndrome. This report also highlights the importance of early intervention with pralidoxime chloride prior to the onset of aging.
Subject(s)
Dog Diseases , Insecticides , Organophosphate Poisoning , Poisoning , Dogs , Animals , Organophosphate Poisoning/drug therapy , Organophosphate Poisoning/veterinary , Pralidoxime Compounds/therapeutic use , Insecticides/therapeutic use , Cholinergic Agents/therapeutic use , Poisoning/drug therapy , Poisoning/veterinary , Dog Diseases/chemically induced , Dog Diseases/drug therapyABSTRACT
This paper reported 1 case of poisoning caused by stramonium. Cases of Datura poisoning have been reported nationwide, Its effect on the central nervous system of patients is characterized by first excitation and then inhibition, clinical manifestations include decreased gland secretion, dilated pupils, and tachycardia, etc. Its poisoning mechanism is anticholinergic effect, the effect on Peripheral nervous system is to inhibit Parasympathetic nervous system. Hemoperfusion combined with neostigmine anticholinergic therapy at the early stage of poisoning can effectively improve the clinical symptoms of patients in a short time.
Subject(s)
Datura stramonium , Plant Poisoning , Poisoning , Humans , Plant Poisoning/diagnosis , Plant Poisoning/therapy , Cholinergic Antagonists/therapeutic use , Poisoning/drug therapyABSTRACT
Study finds dramatic increase in opioid-related fatalities.
Subject(s)
Drug Overdose , Poisoning , Humans , Child , Analgesics, Opioid/therapeutic use , Drug Overdose/drug therapy , Poisoning/drug therapyABSTRACT
Industrial production of food for animals and humans needs increasing amounts of pesticides, especially of organophosphates, which are now easily available worldwide. More than 3 million cases of acute severe poisoning are estimated to occur worldwide every year, and even more cases remain unreported, while 200,000-350,000 incidentally or intentionally poisoned people die every year. Diagnostic and therapeutic procedures in organophosphate poisoning have, however, remained unchanged. In addition to several neurologic symptoms (miosis, fasciculations), hypersecretion of salivary, bronchial, and sweat glands, vomiting, diarrhea, and loss of urine rapidly induce dehydration, hypovolemia, loss of conscience and respiratory distress. Within hours, signs of acidosis due to systemic hypoxia can be observed at first laboratory investigation after hospitalization. While determination of serum-cholinesterase does not have any diagnostic value, it has been established that hypoalbuminemia alone or accompanied by an increase in creatinine, lactate, or C-reactive protein serum levels has negative prognostic value. Increased serum levels of C-reactive protein are a sign of systemic ischemia. Protective mechanical ventilation should be avoided, if possible. In fact, acute respiratory distress syndrome characterized by congestion and increased weight of the lung, accompanied by heart failure, may become the cause of death. As the excess of acetylcholine at the neuronal level can persist for weeks until enough newly, locally synthesized acetylcholinesterase becomes available (the value of oximes in reducing this time is still under debate), after atropine administration, intravenous albumin and fluid infusion should be the first therapeutic interventions to reestablish normal blood volume and normal tissue oxygenation, avoiding death by cardiac arrest.
Subject(s)
Heart Failure , Organophosphate Poisoning , Poisoning , Respiratory Distress Syndrome , Animals , Humans , Organophosphate Poisoning/diagnosis , Acetylcholinesterase , C-Reactive Protein , Cause of Death , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/therapy , Poisoning/diagnosis , Poisoning/drug therapyABSTRACT
In China, the extensive use of the pesticide chlorfenapyr has led to an increase in chlorfenapyr poisoning. However, there are limited reports on chlorfenapyr poisoning, and most of them are fatal cases. This study retrospectively analyzed four patients admitted to the emergency room after chlorfenapyr intake and detected different concentrations of chlorfenapyr in their plasma. Among them, one patient died and three patients survived. Case 1 suffered respiratory and circulatory failure with a deep coma shortly after oral administration of 100 mL of a the chlorfenapyr-containing mixture and died 30 min after admission. Case 2 experienced transient nausea and vomiting after oral administration of chlorfenapyr (50 mL). The patient had normal laboratory results and was discharged with no further treatment. Case 3 developed nausea and vomiting and a light coma after taking 30 mL of chlorfenapyr orally. He underwent blood perfusion and plasma exchange in the intensive care unit (ICU) and was discharged with recovery. A two-week follow-up visit, however, revealed hyperhidrosis. Case 4 (advanced age with severe underlying disease) developed a light coma after oral intake of 30 mL of chlorfenapyr. Subsequently, pulmonary infection and gastrointestinal bleeding were developed. The patient experienced blood perfusion and mechanical ventilation in the ICU and finally survived after treatment. The present study provides the basic information, plasma concentration of toxins, onset of poisoning and treatment process of the four patients mentioned above, providing novel insights into the clinical diagnosis and treatment of chlorfenapyr poisoning.
Subject(s)
Poisoning , Pyrethrins , Male , Humans , Retrospective Studies , Coma/chemically induced , Coma/therapy , Vomiting , Poisoning/drug therapyABSTRACT
Antidote stocking has been described in several studies from many countries to be problematic and constantly insufficient. During our institution's previous experience with a medication event that resulted from lack of antidote stocking, we initiated a review of all our antidotes and realized the lack of data on utilization in the literature that would help us in planning for our stocks. Therefore, we conducted this retrospective review of antidotes utilized at a large tertiary care hospital over a period of 6 years. The paper describes the types of antidotes and toxins involved, together with important patient characteristics and antidote utilization data that can be useful to other healthcare institutions in planning for their antidote stocks.
Subject(s)
Pharmacy Service, Hospital , Poisoning , Humans , Antidotes/therapeutic use , Retrospective Studies , Saudi Arabia , Tertiary Care Centers , Poisoning/drug therapyABSTRACT
Cyanide-a fast-acting poison-is easy to obtain given its widespread use in manufacturing industries. It is a high-threat chemical agent that poses a risk of occupational exposure in addition to being a terrorist agent. FDA-approved cyanide antidotes must be given intravenously, which is not practical in a mass casualty setting due to the time and skill required to obtain intravenous access. Glyoxylate is an endogenous metabolite that binds cyanide and reverses cyanide-induced redox imbalances independent of chelation. Efficacy and biochemical mechanistic studies in an FDA-approved preclinical animal model have not been reported. Therefore, in a swine model of cyanide poisoning, we evaluated the efficacy of intramuscular glyoxylate on clinical, metabolic, and biochemical endpoints. Animals were instrumented for continuous hemodynamic monitoring and infused with potassium cyanide. Following cyanide-induced apnea, saline control or glyoxylate was administered intramuscularly. Throughout the study, serial blood samples were collected for pharmacokinetic, metabolite, and biochemical studies, in addition, vital signs, hemodynamic parameters, and laboratory values were measured. Survival in glyoxylate-treated animals was 83% compared with 12% in saline-treated control animals (p < .01). Glyoxylate treatment improved physiological parameters including pulse oximetry, arterial oxygenation, respiration, and pH. In addition, levels of citric acid cycle metabolites returned to baseline levels by the end of the study. Moreover, glyoxylate exerted distinct effects on redox balance as compared with a cyanide-chelating countermeasure. In our preclinical swine model of lethal cyanide poisoning, intramuscular administration of the endogenous metabolite glyoxylate improved survival and clinical outcomes, and ameliorated the biochemical effects of cyanide.
Subject(s)
Cyanides , Poisoning , Swine , Animals , Cyanides/toxicity , Disease Models, Animal , Antidotes/pharmacology , Antidotes/therapeutic use , Hemodynamics , Glyoxylates/therapeutic use , Poisoning/drug therapyABSTRACT
La intoxicacioÌn por paracetamol de causa no intencional en niños pequeños, e intencional en adolescentes es un motivo de consulta cada vez más frecuente en los servicios de urgencia. La gravedad y el pronoÌstico de esta intoxicacioÌn están dados por el riesgo de falla hepática. Ante la sospecha de ingesta de paracetamol, se debe conocer el tiempo transcurrido, la cantidad de ingesta del fármaco, estimar la toxicidad de la dosis ingerida para predecir hepatotoxicidad, determinar las medidas de contaminacioÌn necesarias, dosificar paracetamol en sangre y evaluar la necesidad de administración de antídoto. Se describe el caso de una adolescente que con intencioÌn suicida presentoÌ una intoxicacioÌn aguda por paracetamol con riesgo de daño hepático requiriendo decontaminación digestiva, administración de antídoto y abordaje interdisciplinario de sus problemas psicoemocionales.
Paracetamol intoxication due to an unintentional cause in young children, and intentional in adolescents, is an increasingly frequent cause for consultation in emergency services. The severity and prognosis of this poisoning is due to the risk of liver failure. Given the suspicion of paracetamol ingestion, the time passed since the ingestion, the amount of paracetamol ingested, the estimate of the dose ingested to predict hepatotoxicity, we must determine the necessary decontamination measures and the paracetamol dose in blood and evaluate the need to administer a paracetamol antidote. We describe the case of an adolescent who presented acute paracetamol poisoning with risk of liver damage resulting from a suicide attempt and who required digestive decontamination, antidote administration and an interdisciplinary approach to her psychological and emotional problems.
A intoxicação não intencional por paracetamol em crianças pequenas e a intoxicação intencional em adolescentes é um motivo cada vez mais comum de consulta em serviços de emergência. A gravidade e o prognoÌstico desse envenenamento são dados pelo risco de insuficiência hepática. Quando há suspeita de ingestão de paracetamol, o tempo decorrido desde que é ingerido, a quantidade de paracetamol ingerida, a estimação da dose ingerida para predizer hepatotoxicidade, utilizamse para determinar as medidas de contaminação necessárias, dosar paracetamol no sangue e avaliar a ne- cessidade de administração de antídoto. Descrevemos o caso de uma adolescente com intenção suicida que apresentou intoxicação aguda por paracetamol com risco de lesão hepática com necessidade de descontaminação digestiva, administração de antídoto e abordagem interdisciplinar de seus problemas psicoemocionais.
Subject(s)
Humans , Female , Child , Poisoning/drug therapy , Charcoal/therapeutic use , Acetaminophen/poisoningABSTRACT
INTRODUCTION AND OBJECTIVE: Pesticide poisoning induced cardiac arrest (PPICA) has rarely been reported before, and can easily be overlooked by physicians. The aim of the study was to investigate the clinical characteristics of PPICA patients. METHODS: This was a single-center, retrospective analysis in the emergency intensive care unit (EICU) at tertiary medical facility, from January 2015 to December 2018. RESULTS: A total of 15 patients with PPICA in EICU were included, of which nine were females, where suicide was the only cause of poisoning. Thirteen were in-hospital cases and only three cases showed an initial shockable rhythm. On admission, patients' median acute physiology and chronic health evaluation II score was 20 (12, 21) and median sequential organ failure assessment score was 7 (4, 10). All cases required invasive mechanical ventilation and vasopressors therapy. Seven patients received blood purification therapy. The primary toxic agent was organophosphorus pesticide (OP) and all OP cases (8/15) received pralidoxime and atropine therapy. Thirteen patients received gastric decontamination. The primary complications were cardiogenic shock (10/15) and acute kidney injury (3/15). Seven patients survived at discharge. Of these, three made a full recovery without neurological sequelae. CONCLUSIONS: Cardiac arrest has rarely been reported in pesticide poisoning before, and can easily be overlooked. Physicians therefore should pay attention to specific therapy and best supportive treatment, which could be critical to improve the disease outcomes.
Subject(s)
Heart Arrest , Pesticides , Poisoning , Female , Humans , Male , Retrospective Studies , Organophosphorus Compounds , Heart Arrest/chemically induced , Heart Arrest/therapy , Atropine/therapeutic use , Poisoning/therapy , Poisoning/drug therapyABSTRACT
Introducción: El uso de productos de limpieza, a expensa de los desinfectantes se ha incrementado por la población mundial como consecuencia de la COVID-19. El manejo frecuente de estas sustancias químicas por las personas puede ocasionar cuadros de intoxicaciones agudas. Esta situación se evidencia en los reportes emitidos por los centros antitóxicos del orbe, donde consta el aumento en el número de consultas toxicológicas. Objetivo: Describir el tratamiento de las intoxicaciones agudas por desinfectantes durante la COVID-19. Métodos: Se realizó una revisión bibliográfica acerca del tratamiento de las intoxicaciones agudas por desinfectantes durante la COVID-19. Se incluyeron artículos escritos en español, inglés y portugués. Además, se abordaron aspectos relacionados con las intoxicaciones agudas por el uso de desinfectantes, el cuadro clínico, así como elementos del diagnóstico y tratamiento de las intoxicaciones agudas por estas sustancias químicas. Conclusiones: Las intoxicaciones agudas por hipoclorito de sodio y geles hidroalcohólicos son las más frecuentes en la población durante la COVID-19 en proporción con el uso de estos productos químicos. La atención médica precoz, eficaz y oportuna disminuirá la posibilidad de aparición de complicaciones. El tratamiento de estás intoxicaciones agudas está en relación con los síntomas y signos que presentan los pacientes al ser recibidos en los servicios de urgencia(AU)
Introduction: The use of cleaning products, at the expense of disinfectants, has increased by the world population as a consequence of COVID-19. Frequent handling of these chemical substances by people can cause acute poisoning. This situation is evidenced in the reports issued by the world's anti-toxic centers, where the increase in the number of toxicological consultations is recorded. Objective: To describe the treatment of acute poisoning by disinfectants during COVID-19. Methods: A literature review on the treatment of acute poisoning by disinfectants during COVID-19 was carried out. Articles written in Spanish, English and Portuguese were included. In addition, aspects related to acute poisoning due to the use of disinfectants, the clinical condition, as well as elements of the diagnosis and treatment of acute poisoning by these chemical substances were addressed. Conclusions: Acute poisoning by sodium hypochlorite and hydroalcoholic gels are the most frequent in the population during COVID-19 in proportion to the use of these chemical products. Early, effective and timely medical care will reduce the possibility of complications. The treatment of these acute intoxications is related to the symptoms and signs presented by patients when they are received in the emergency services(AU)
Subject(s)
Humans , Male , Female , Poisoning/drug therapy , Sodium Hypochlorite/adverse effects , Disinfectants/poisoning , Hand Sanitizers/adverse effects , COVID-19ABSTRACT
Colchicine is a tricyclic, lipid-soluble alkaloid which has long been used to treat gout and many immunological diseases. Due to its narrow therapeutic window and long half-life of elimination, colchicine overdose occurs occasionally. Unfortunately, some patients lost their lives because of colchicine overdose or suicide. Acute colchicine poisoning can lead to original gastrointestinal disorders, shock, progressive multiple organ failure, and myelosuppression. Although many researchers in the world performed lots of research, there are currently no specific antidotes for colchicine poisoning. Meanwhile, there are no management guidelines to treat patients with acute colchicine poisoning until now. Herein, we systematically elaborate on the clinical features and progress in the management of acute colchicine poisoning in adults according to the previous literature. This paper will provide some valuable and available information for clinicians.
Subject(s)
Poisoning , Suicide , Adult , Antidotes/therapeutic use , Colchicine/therapeutic use , Humans , Lipids , Multiple Organ Failure , Poisoning/drug therapyABSTRACT
La emulsiones lipídicas intravenosas (ELI) se han utilizado ampliamente para el tratamiento de la intoxicación por anestésicos locales (AL) y se han propuesto como tratamiento de la intoxicación por otros fármacos. Sin embargo, el grado de evidencia de este tipo de terapias no es sólido, ya que proviene en su mayoría de casos clínicos. El objetivo de esta revisión narrativa es describir los mecanismos de acción propuestos para las ELI en la intoxicación por AL y otros fármacos, y evaluar los estudios recientes realizados en animales que sustentan las recomendaciones de su uso y la experiencia en humanos que apoyan el empleo de las ELI tanto en la intoxicación por AL como por otros fármacos. Para ello, se llevó a cabo una búsqueda en las bases de datos Embase, Medline, Cochrane y Google Scholar abarcando los artículos relevantes durante los últimos 10 años. En caso de intoxicación por AL, se recomienda aplicar los protocolos dictados por las guías internacionales, sabiendo que el grado de evidencia no es muy elevado. En la intoxicación por otros fármacos, las ELI están aconsejadas en situaciones graves inducidas por xenobióticos liposolubles que no responden al tratamiento estándar.(AU)
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.(AU)
Subject(s)
Humans , Animals , Male , Female , Fat Emulsions, Intravenous/administration & dosage , Fat Emulsions, Intravenous/therapeutic use , Poisoning/drug therapy , Anesthetics, Local/adverse effects , Anesthetics, Local/toxicity , Pharmaceutical Preparations , Toxicity/adverse effects , Toxicity/prevention & control , Fat Emulsions, Intravenous/pharmacology , Fat Emulsions, Intravenous/pharmacokinetics , Anesthesiology , XenobioticsABSTRACT
Hydrogen sulfide (H2S) induces acute and lethal toxicity at high concentrations. However, no specific antidotes for H2S poisoning have been approved. Liposomal methemoglobin (metHb@Lipo) was developed as an antidote for cyanide poisoning. As the toxic mechanism of H2S poisoning is the same as that of cyanide poisoning, metHb@Lipo could potentially be used as an antidote for H2S poisoning. In this study, we evaluated the antidotal efficacy of metHb@Lipo against H2S poisoning. Stopped-flow rapid-scan spectrophotometry clearly showed that metHb@Lipo scavenged H2S rapidly. Additionally, metHb@Lipo showed cytoprotective effects against H2S exposure in H9c2 cells by maintaining mitochondrial function. MetHb@Lipo treatment also improved the survival rate after H2S exposure in vivo, with the maintenance of cytochrome c oxidase activity and suppression of metabolic acidosis. Moreover, metHb@Lipo therapy maintained significant antidotal efficacy even after 1-year-storage at 4-37 °C. In conclusion, metHb@Lipo is a candidate antidote for H2S poisoning.