Phosphide poisoning: A review of literature

Modulating oxidative stress, apoptosis, and mitochondrial dysfunctions on cardiotoxicity induced by aluminum phosphide pesticide using resveratrol

The agricultural fumigant pesticide aluminum phosphide (AlP) is cardiotoxic. Water causes AlP to emit phosphine gas, a cardiac toxin that affects heart function and causes cardiogenic shock. AlP poisoning's high fatality rate is due to cardiotoxicity. This study examines how resveratrol reduces oxidative stress, mitochondrial activity, and apoptosis in human cardiac myocyte (HCM) cells. After determining the optimal doses of resveratrol using the MTT test, HCM cells were subjected to a 24-h treatment of resveratrol following exposure to AlP (2.36 μM). The levels of reactive oxygen species (ROS), superoxide dismutase (SOD) activity, mitochondrial swelling, mitochondrial cytochrome c release, and mitochondrial membrane potential (MMP) in HCM cells were investigated. Also, the expression of Bax and Bcl-2, caspace-3 activity, and apoptosis were assessed. The present investigation revealed that AlP substantially increased the level of ROS and decreased SOD activation, which were significantly modulated by resveratrol in a dose-dependent manner. Moreover, AlP induced an elevation of mitochondrial swelling, cytochrome c release, and MMP collapse. Co-administration of resveratrol significantly reduced above mitochondrial markers. AlP also significantly upregulated BAX and downregulated Bcl-2 expression, elevated caspace-3 activity, and apoptosis. Resveratrol co-administration was able to meaningfully modulate the mentioned parameters and finally reduce apoptosis. In conclusion, resveratrol, via its pleotropic properties, significantly demonstrated cytoprotective effects on HCM cytotoxicity induced by AlP.

In vivo treatment of zinc phosphide poisoning by administration of mesoporous silica nanoparticles as an effective antidote agent

Mesoporous silica nanoparticles (MSNs) are highly advanced engineered particles with increased surface area and extreme adsorption capacity for various molecules. Herein, two types of MSNs were synthesized and applied as adsorbents for phosphine gas. One was without functional groups (MSN), and the other was post-modified with boric acid (MSN-BA). The structures of MSN and boric acid-modified MSN with high surface areas of about 1025 and 650 m2/g, respectively, were defined. MSN was found to have particles with sizes around 30 nm by transmission electron microscopy (TEM). In the present study, MSNs were used as an antidote to phosphorus poisoning, and zinc phosphide (phosphorus) powder was used as the toxic and lethal agent. In vivo analysis was carried out on rats to demonstrate the ability of MSNs to chemisorb phosphine gas. In the survival percentage assessment, Phos-poisoned animals were kept alive after treatment with MSNs, and the MSN-BA-treated group (dose of 5 mg/kg) was shown to have a 60 % survival rate. Blood serum analysis showed that MSNs have a high potential to alleviate organ blood damage, and serum biomarkers dropped sharply while phosphine-poisoned animals were treated with MSN-BA.

The first reported mortality from aluminum phosphide poisoning in Lebanon: a case report

BACKGROUND

Aluminum phosphide is a commonly used pesticide, particularly in developing countries where uncontrolled insecticides and pesticides are commonly prevalent. Mortalities have been reported due to accidental and suicidal exposures to aluminum phosphide. To date, there has been no reported mortality case of aluminum phosphide in Lebanon. In addition, there is no specific antidote for aluminum phosphide toxicity and the treatment is mainly supportive. This is why awareness should be spread about this case to include it in the differential diagnoses and enhance prompt management and response in future encounters.

CASE PRESENTATION

A previously healthy 37-year-old male, presented to the emergency department of Notre Dame des Secours University Hospital Center for a suicidal attempt after ingesting 5 tablets of pesticide containing 56% aluminum phosphide an hour prior to presentation. Shortly after the presentation, the patient began deteriorating and became clinically unstable. The patient was then intubated and was started on sodium bicarbonate along with aggressive fluid resuscitation. The patient remained hypotensive even after giving vasopressors. He was then later admitted to the intensive care unit for further management. However, the patient further decompensated and developed multiorgan failure. This is the first case of mortality in Lebanon from aluminum phosphide toxicity.

CONCLUSIONS

Emergency physicians should include aluminum phosphide toxicity in the differential diagnosis when dealing with patients ingesting unknown pesticides especially when they smell the characteristic garlic-like odor. The toxicity from ALP leads to multiorgan failure and death rapidly. Thus, it is of utmost importance to start early, and aggressive resuscitation given that there is no specific antidote.

Impact of aluminum phosphide on development of the forensically important fly, Chrysomya albiceps (Diptera: Calliphoridae)

Chrysomya albiceps (Calliphoridae) is among the earliest successional fauna on human and animal cadavers. Some immature Calliphoridae can be useful for determination of post-mortem interval. Toxins, particularly pesticides, can affect the rate of insect growth. Aluminum phosphide (AlP) is an affordable insecticide that has not been adequately entomotoxicologically evaluated. So, the impact of AlP on the developmental rate of different stages of C. albiceps was investigated. Larvae of C. albiceps were reared on the rabbit carcasses containing AlP as a treated group, and distilled water as a control group. The substances were administered by a gastric tube. The duration needed for development of C. albiceps stages was documented. Body length, width and weight of larvae were measured after 24, 48, 72 and 96 h from egg hatching. The duration of development increased significantly in the treated group compared to the control group. Larvae body measurements were significantly smaller in the treated group than in the control group. Therefore, it was demonstrated that AlP significantly influences the size of C. albiceps larvae and extends their development. During forensic application, interpretation of C. albiceps data should be used with caution when aluminum phosphide may be the cause of death.

The therapeutic effect of a novel parenteral formulation of dihydroxyacetone in aluminum phosphide-intoxicated patients

Background and objectives

Aluminum phosphide (AlP), known as "rice tablet," is widely used as an effective pesticide. However, AlP poisoning is a common cause of mortality in many countries, such as Iran. Unfortunately, there is no specific antidote for AlP toxicity to date. AlP releases phosphine gas when it is exposed to moisture or acid. Phosphine is a potent mitochondrial toxin that could significantly inhibit cellular energy metabolism. AlP poisoning is an emergency condition that needs instant and effective intervention. Dihydroxyacetone (DHA) is a simple saccharide used for several pharmacological as well as cosmetic purposes. Previously, we found that DHA could significantly prevent mitochondrial impairment induced by toxic agents such as cyanide and phosphine in various in vitro and in vivo experimental models.

Methods

Hospitalized patients (n = 111) were evaluated for eligibility criteria. Among these patients, n = 35 cases were excluded due to incomplete data (n = 11) and suspicion of poisoning with poisons other than AlP (n = 24). Meanwhile, n = 76 cases with confirmed AlP poisoning were included in the study. AlP-poisoned patients who did not receive DHA (n = 18) were used as the control group.Patients (n = 58) received at least one dose of DHA (500 ml of 5 % DHA solution w/v, i.v.) as an adjuvant therapy in addition to the routine treatment of AlP poisoning. Arterial blood gas (ABG), blood pH, bicarbonate levels, and other vital signs and biochemical measurements were monitored. Moreover, the mortality rate and hospitalization time were evaluated in DHA-treated and AlP-poisoned patients without DHA administration. Several biomarkers were assessed before (upon hospitalization) and after DHA treatment. The routine tests for AlP-poisoned patients in this study were the measurement of electrolytes (K+ and Na+), WBC, RBC, hemoglobin, INR, carbonate (HCO3), blood pH, PaCO2, and PaO2 and SGPT, SGOT, BUN, Cr.

Results

Upon patients' admission, significant decreases in blood pH (acidosis), blood PaO2, and HCO3 levels were the hallmarks of AlP poisoning. It was found that DHA significantly alleviated biomarkers of AlP poisoning and tremendously enhanced patients' survival rate (65.52 % in DHA-treated vs 33.34 % in the control group) compared to patients treated based on hospital routine AlP poisoning protocols (no DHA). No significant adverse effects were evident in DHA-treated patients in the current study.

Interpretation and conclusions

These data suggest that parenteral DHA is a novel and effective antidote against AlP poisoning to be used as an adjuvant in addition to routine supportive treatment.

Trial registration

IR.SUMS.REC.1394.102.

Induction of Brugada electrocardiogram pattern with aluminum phosphide poisoning: a case report

Introduction and importance

Aluminum phosphide (ALP) is a commonly used suicidal agent in an agrarian country like Nepal. The unmasking of the Brugada pattern in the electrocardiogram (ECG) associated with ALP poisoning is a rare phenomenon, and studies pertaining to it are scarce in the medical literature.

Case presentation

An 18-year-old female presented to the emergency department with multiple episodes of vomiting, headache, blurring of vision, and abdominal pain after 4 h of consumption of ALP with suicidal intent. A 12-lead ECG revealed a coved ST-segment elevation and T-wave inversion in leads V1-V3 with right bundle branch block suggestive of a type 1 Brugada pattern. Her past medical and family history was not significant. The patient made an uneventful recovery with the required supportive treatments.

Clinical discussion

Cardiac arrhythmias are the major cause of death in ALP poisoning. Unmasking of the Brugada ECG pattern is a rare but potentially fatal complication implicated in various pharmacological toxicities, including tricyclic antidepressants, cocaine, procainamide, disopyramide, flecainide, and rarely with ALP.

Conclusions

ALP poisoning can unmask the Brugada ECG pattern, which can lead to ventricular fibrillation and/or sudden cardiac death.

Zinc Phosphide Poisoning: From A to Z

Zinc phosphide is a rodenticide that is used in agricultural, urban and industrial environments in México. After ingestion, it reacts with hydrochloric acid, hydrolyzing into phosphine. It causes cellular hypoxia via mitochondrial toxicity, resulting in multiple organ dysfunction and death. There is no antidote or specific treatment for zinc phosphide toxicity. We present the case of a 45-year-old female who ingested zinc phosphide with suicidal intent. On arrival at the emergency department, she had multisystemic disorders. Supportive care, decontamination and antidotal therapy were initiated. Subsequently, she evolved to clinical improvement with a resolution of the biochemical abnormalities of tissue hypoperfusion. She was discharged on day 7 without complications. In this review, we provide updated therapeutic options and discuss their specific pathophysiological basis.

Visual impairment following aluminum phosphide poisoning: A rare case

Key Clinical Message

Aluminum phosphide poisoning may cause rare visual impairment. In a case, a 31-year-old female, visual loss was linked to shock-induced hypoperfusion, causing oxygen lack and cerebral atrophy, emphasizing the need for identifying atypical symptoms.

Abstract

This case report describes the multidisciplinary evaluation of a 31-year-old female patient who suffered from visual impairment as a result of aluminum phosphide (AlP) poisoning. Phosphine, which is formed in the body when AlP reacts with water, cannot cross the blood-brain barrier; therefore, visual impairment seems unlikely to be the direct result of phosphine. To our knowledge, it is the first documented report of such impairment due to AlP.

Repurposing of sevelamer as a novel antidote against aluminum phosphide poisoning: An in vivo evaluation

Aluminum phosphide (AlP) is widely used for protecting grains from pests. AlP releases toxic phosphine gas (PH₃) while exposed to humidity. Poisoning with these tablets is dangerous and can cause death or serious injuries. Up to now, no definite antidote has been introduced for specific treatment of this poisoning. Sevelamer carbonate or sevelamer hydrochloride (Renagel) is a polymeric pharmaceutical prescribed for treating hyperphosphatemia in patients with chronic kidney disease. Sevelamer can bind with phosphate groups and act as an anion exchanger. Herein, sevelamer is repurposed as a potent antidote agent in phosphine gas poisoning. In vivo evaluation was conducted on male Sprague Dawley rats. The evaluation was conducted on three groups of animals: control, AlP-poisoned, and AlP-poisoned treated with sevelamer. Survival percentage, serum biomarkers level of organ injury, and ATP level were recorded. The results indicate a high survival rate in sevelamer-treated animals compared with the AlP-poisoned group (75% vs. 0% respectively, 48 h after poisoning). The analysis of serum markers of organ injury also showed that sevelamer could reduce toxicity and organ injury in poisoned animals. ATP level of separate organs showed that sevelamer treated groups were recovered. The results showed that sevelamer could be a potent antidote for managing aluminum phosphide poisoning. Moreover, a mechanism is suggested for the interaction of sevelamer with phosphine gas.

Case Report: Acute Intoxication from Phosphine Inhalation

Aluminum phosphide is a highly effective insecticide for fumigation in granaries and is often used in rural grain storage. However, people's awareness of its toxicity is not strong. A case of acute inhalation toxicity of phosphine caused by the use of aluminum phosphide to fumigate a granary is reported here. The case presented with aspiration pneumonia and acute left heart failure. The patient was cured using comprehensive life support treatment, including respiratory support, antiarrhythmic treatment, and blood pressure maintenance with vasoactive drugs. There is no specific antidote for phosphine poisoning at present, and the comprehensive application of restricted fluid resuscitation, high-dose glucocorticoid shock, vasoactive drugs and bedside hemofiltration is significant in improving the prognosis of patients. It is also important to remind people to pay attention to their own protection in the process of using aluminum phosphide.

Research Trends, Biases, and Gaps in Phytochemicals as Insecticides: Literature Survey and Meta-Analysis

A 76-year literature survey and meta-analyses were carried out to recognize the trends, biases, and knowledge gaps of studies focusing on major groups of compounds of botanical origin, or phytochemicals, as insecticides. The survey found that the main phytochemicals prospected as insecticides belong to the following major chemical groups: terpenoids, terpenes, and carbonyl, all of which were tested, mainly against beetles (Coleoptera), caterpillars (i.e., larvae of Lepidoptera), and mosquitoes and other flies (i.e., Diptera). These studies are burgeoning at an exponential rate, with an evident focus on mortality endpoint estimates, but they are also neglecting sublethal assessments. China and India in Asia, as well as Brazil in the Americas, were responsible for most studies. The majority of the papers used stored grain insects as experimental models, which limits the applicability and representativeness of the findings. As a result, the main modes of exposure tested were fumigation and contact, which leads to the prevalence of estimates of lethal concentration in these studies. Therefore, a broader range of insect species deserves testing, with suitable modes of exposure identifying and characterizing the main molecules responsible for the insecticidal activity, which is seldom performed. Attention to these needs will circumvent current biases and allow the recognition of the main patterns of association between the origin and structure of phytochemicals and their insecticidal effects.

Refractory cardiogenic shock caused by zinc phosphide toxicity

Zinc phosphide toxicity is a rare entity that presents most frequently among farmers in developing countries who use it as a rodenticide. The phosphine gas released after the ingestion inhibits cytochrome c oxidase, disrupting the mitochondrial physiology and oxidative phosphorylation and causing myocardial stunning. Here we present a case of a 20-year-old man who attempted suicide with zinc phosphide toxicity. Initially, he was hemodynamically stable with a normal ejection fraction; however, in a few hours, he deteriorated quickly and became hemodynamically unstable, with rapid deterioration of his ejection fraction to 20%. He was started on norepinephrine and then dobutamine; however, he had cardiac arrest from refractory cardiogenic shock despite resuscitative measures.

Nanocurcumin Improves Lipid Status, Oxidative Stress, and Function of the Liver in Aluminium Phosphide-Induced Toxicity: Cellular and Molecular Mechanisms

Background

The present study aimed to evaluate the effect of nanocurcumin and curcumin on liver transaminases, lipid profile, oxidant and antioxidant system, and pathophysiological changes in aluminium phosphide (ALP) induced hepatoxicity. Material and Methods. In this experimental study, thirty-six male Wistar rats were randomly divided into six groups curcumin (Cur), nanocurcumin (Nanocur), ALP, ALP+Cur, and ALP+Nanocur. All treatments were performed by oral gavage for seven days. After treatment, animals were sacrificed, and liver and blood samples were taken. Serum levels of aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (AP), total bilirubin, cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) were measured by photometric methods. Total antioxidant capacity (TAC) and malondialdehyde (MDA) as parameters of oxidative stress and mRNA expression of the nonenzyme protein including Sirtuin 1 (STR1), Forkhead box protein O1 (FOXO1) and protein O3 (FOXO3), catalase (CAT), and glutathione peroxidase (GPX) as the enzyme protein in homogenized tissues have been investigated. A histologist analyzed liver tissue sections after staining with hematoxylin-eosin.

Results

In the aluminium phosphide group, there was a significant increase in MDA, ALT, AST, and AP and total bilirubin, cholesterol, triglyceride, LDL, and VLDL; AST, ALT, total bilirubin, LDL, VLDL, cholesterol, and MDA were significantly decreased; and HDL and TAC were significantly increased compared to ALP (P < 0.05). In the ALP+Nanocur group, ALT, AST, ALP, total bilirubin, cholesterol, LDL, VLDL, triglyceride, and MDA were significantly decreased and HDL and TAC were increased significantly (P < 0.05). The effect of nanocurcumin on controlling serum levels of LDL, VLDL, triglyceride, and MDA in ALP-poisoned rats was significantly more than curcumin (P < 0.05). The ALP group had significant changes in genes SIRT1, FOXO1a, FOXO3a, CAT, and GPX compared to healthy controls (P < 0.05). Nanocurcumin mice expressed more SIRT1, FOXO1a, CAT, and GPX genes than controls, and curcumin-treated mice expressed more SIRT1 and FOXO1a genes (P < 0.05). Histopathological findings also indicated a more significant protective effect of nanocurcumin relative to curcumin against ALP-induced hepatotoxicity.

Conclusion

Nanocurcumin significantly protects the liver against aluminum phosphide toxicity. It is suggested that nanocurcumin-based drugs be developed to reduce the toxic effects of ALP in poisoned patients.

Clinical manifestations and treatment management of hospitalized patients with zinc phosphide poisoning, Mazandaran Province, Northern Iran

Background

Zinc phosphide (ZnP) is a dark gray crystalline compound used as a rodenticide against rodents such as mice. ZnP poisoning may be accidental or suicidal. The aim of this study was to investigate the clinical manifestations and treatment management of hospitalized patients with ZnP poisoning in Mazandaran Province, northern Iran.

Methods

Between 2013 and 2017, a cross-sectional study was performed on hospitalized patients with ZnP poisoning who were referred to two training hospitals in Mazandaran Province, northern Iran.

Results

A total of 127 patients participated in this trial, including 71 (55.9%) men and 56 (44.1%) women. The patients’ average (standard deviation) age was 25.5 (±16.82) years, and it took 2.18 (±2.23) hours to refer them to the hospital. There were 42 (33%) cases with less than one package, 9 (7%) cases with several packages, and 76 (60%) cases with no particular usage.

Conclusions

This study has shown that ZnP poisoning may be asymptomatic initially or with mild clinical symptoms that may gradually worsen. Therefore, hospitalization and obtaining a history and a careful physical examination should be considered.

Reduced body length and morphological disorders in Chrysomya albiceps (Diptera: Calliphoridae) larvae reared on aluminum phosphide-treated rabbits

Assessing the time of death based on the growth and development of insects is a critical task in forensic entomology. The rate of larvae development can be affected by a variety of toxins, including pesticides. Aluminum phosphide (AlP) is a low-cost insecticide that has yet to be tested for entomotoxicological significance, despite the fact that it is frequently the cause of fatal poisoning. In this study, we measured the body length of Chrysomya albiceps larvae reared on the carcasses of rabbits poisoned with AlP and analyzed the morphological changes of the larvae reared on the carcasses of rabbits poisoned with AlP. The concentration of AlP in the body of the larvae was significantly lower than in rabbit tissues. Insects from the AlP group had a significantly lower gain in body length. Furthermore, deformities in the larvae were found. Smaller respiratory spiracles were found, as well as a deformed small posterior end with hypogenesis of the posterior respiratory spiracles. Thus, disturbed growth and development of carrion flies found at a crime scene could indicate pesticide poisoning, such as aluminum phosphide.

The Role of Echocardiographic Findings in Estimating Survival Probability of Intensive Care Unit Admitted Aluminum Phosphide Poisoned Patients

INTRODUCTION

Cardiotoxicity represents the primary cause of death in acute aluminum phosphide (AlP) poisoning. Prompt supportive care can improve patient survival. This study assessed the role of echocardiography in estimating the survival probability of AlP-poisoned patients admitted to the intensive care unit.

METHODS

A prospective cohort study of symptomatic acute AlP poisoned patients was conducted between September 2019 and December 2020. Patients were subjected to history taking, clinical examination, To be included, patient evaluation needed to include electrocardiographic (ECG) and echocardiographic studies. The statistical analysis assessed the association between patient survival and relevant factors. Survival analysis was performed using the Kaplan-Meier survival curve and Cox proportional hazard regression.

RESULTS

A total of 90 patients met inclusion criteria. Electrocardiographic abnormalities were detected in 38.1% of survivors and 82.6% of non-survivors (p < 0.001). Survivors had a higher mean left ventricle ejection fraction (LVEF) (50.86 ± 6.30% vs. 26.52 ± 7.64%, respectively, p < 0.001) and a lower percentage of global LV hypokinesia (4.8% vs. 94.2%, p < 0.001). The mean survival time was higher among patients with LVEF ≥ 50% than those with LVEF = 41-49% and ≤ 40% (p = 0.014 and 0.001, respectively). The hazard of death was 4.42 and 5.40 times greater in patients with LVEF ≤ 40% or with global LV hypokinesia, respectively. Regression revealed that the global LV hypokinesia, ECG abnormalities, and decreased LVEF and oxygen saturation were significantly associated with the risk of death (hazard ratios: 4.382, 3.348, 0.957, and 0.971, respectively).

CONCLUSIONS

Echocardiography represents a valuable diagnostic tool to assess cardiac function in acute AlP poisoning. Both LVEF and global LV hypokinesia significantly impact the survival of AlP-poisoned patients. Echocardiography was superior to ECG changes in terms of accuracy for the prediction of mortality.

Antioxidant Potential and Inhibition of Mitochondrial Permeability Transition Pore by Myricetin Reduces Aluminium Phosphide-Induced Cytotoxicity and Mitochondrial Impairments

Oxidative stress and mitochondrial dysfunction are involved in the mechanisms of cardiac toxicity induced by aluminum phosphide (AlP). AlP-induced cardiotoxicity leads to cardiomyocyte death, cardiomyopathy, cardiac dysfunction, and eventually severe heart failure and death. Importantly, protecting cardiomyocytes from death resulting from AlP is vital for improving survival. It has been reported that flavonoids such as myricetin (Myr) act as modifiers of mitochondrial function and prevent mitochondrial damage resulting from many insults and subsequent cell dysfunction. In this study, the ameliorative effect of Myr, as an important antioxidant and mitochondrial protective agent, was investigated in cardiomyocytes and mitochondria isolated from rat heart against AlP-induced toxicity, oxidative stress, and mitochondrial dysfunction. Treatment of AlP (20 μg/ml) significantly increased cytotoxicity; reduced glutathione (GSH) depletion, cellular reactive oxygen species (ROS) formation, malondialdehyde (MDA) level, ATP depletion, caspase-3 activation, mitochondrial membrane potential (ΔΨm) collapse, and lysosomal dysfunction; and decreased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in intact cardiomyocytes. Also, treatment of AlP (20 μg/ml) significantly increased mitochondrial dysfunction and swelling in isolated mitochondria. Myr (80 µM) appeared to ameliorate AlP-induced cytotoxicity in isolated cardiomyocytes; significantly lessened the AlP-stimulated intracellular ROS and MDA production and depletion of GSH; and increased the activities of SOD, CAT, and GSH-Px. Furthermore, Myr (40 and 80 µM) lowered AlP-induced lysosomal/mitochondrial dysfunction, ATP depletion, and caspase-3 activation. In the light of these findings, we concluded that Myr through antioxidant potential and inhibition of mitochondrial permeability transition (MPT) pore exerted an ameliorative role in AlP-induced toxicity in isolated cardiomyocytes and mitochondria, and it would be valuable to examine its in vivo effects.

Brugada Syndrome: Warning of a Systemic Condition?

Brugada syndrome (BrS) is a hereditary disorder, characterized by a specific electrocardiogram pattern and highly related to an increased risk of sudden cardiac death. BrS has been associated with other cardiac and non-cardiac pathologies, probably because of protein expression shared by the heart and other tissue types. In fact, the most commonly found mutated gene in BrS, SCN5A, is expressed throughout nearly the entire body. Consistent with this, large meals and alcohol consumption can trigger arrhythmic events in patients with BrS, suggesting a role for organs involved in the digestive and metabolic pathways. Ajmaline, a drug used to diagnose BrS, can have side effects on non-cardiac tissues, such as the liver, further supporting the idea of a role for organs involved in the digestive and metabolic pathways in BrS. The BrS electrocardiogram (ECG) sign has been associated with neural, digestive, and metabolic pathways, and potential biomarkers for BrS have been found in the serum or plasma. Here, we review the known associations between BrS and various organ systems, and demonstrate support for the hypothesis that BrS is not only a cardiac disorder, but rather a systemic one that affects virtually the whole body. Any time that the BrS ECG sign is found, it should be considered not a single disease, but rather the final step in any number of pathways that ultimately threaten the patient's life. A multi-omics approach would be appropriate to study this syndrome, including genetics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and glycomics, resulting eventually in a biomarker for BrS and the ability to diagnose this syndrome using a minimally invasive blood test, avoiding the risk associated with ajmaline testing.

Evaluation of Protective Effects of Curcumin and Nanocurcumin on Aluminium Phosphide‑Induced Subacute Lung Injury in Rats: Modulation of Oxidative Stress through SIRT1/FOXO3 Signalling Pathway

OBJECTIVE

Aluminum phosphide (AlP) is widely used to protect stored food products and grains from pests and rodents. The availability of AlP, especially in Asian countries it has become a desirable factor to commit suicide. The phosphine produced from ALP is a very reactive radical and a respiratory inhibitor that causes oxidative damage. There is no dedicated antidote or effective drug to manage AlP-induced lung toxicity. The present study aims to evaluate and compare the protective effects of curcumin and nanocurcumin on ALP‑induced subacute lung injury and determine the underlying mechanism.

METHODS

Rats were exposed to AlP (2 mg/kg/day, orally)+curcumin or nanocurcumin (100 mg/kg/day, orally) for 7 days. Then rats were anesthetized and lung tissues were collected. Oxidative stress biomarkers, genes expression of antioxidant enzymes, participated genes in the SIRT1/FOXO3 pathway, and lung histopathology were assessed by biochemical and ELISA methods, Real-Time PCR analysis, and H&E staining.

RESULTS

Curcumin and nanocurcumin produced a remarkable improvement in AlP-induced lung damage through reduction of MDA, induction of antioxidant capacity (TAC, TTG) and antioxidant enzymes (CAT, GPx), modulation of histopathological changes, and up-regulation of genes expression of SIRT1, FOXO3, FOXO1 in lung tissue.

CONCLUSION

Nanocurcumin had a significantly more protective effect than curcumin to prevent AlP-induced lung injury via inhibition of oxidative stress. Nanocurcumin could be considered a suitable therapeutic choice for AlP poisoning.

Fatalities Due to Poisoning with Aluminum Phosphide (Rice Pill) and Methadone

Acute poisoning is commonly seen with pharmaceutical substance or pesticides. Understanding pattern of acute poisoning due to different agents can enable better emergency management. The aim of this study is to present and evaluate the fatality-related data of acute poisoning due to aluminum phosphide (rice pills) and methadone. This descriptive-analytical study was performed on patients Shahid Rahimi Hospital due to poisoning with rice tablets (aluminum phosphide) and methadone from 2015-2020. The data collection tool was a questionnaire using with demographic data, type and dose of poison and clinical presentation, duration of hospitalization was obtained and statistically analyzed. Out of 19 238 patients with poisoning referred to this center, 412 people referred to the hospital due to rice pill poisoning, of which 56 (13.59%) died and among 2157 patients due to methadone poisoning, 22 of them (1.09%) died. In both the groups, rice pill and methadone, there were more male patients 53.57 and 81.81%, respectively. In aluminum phosphide poisoning, the greatest population was in the age group (15-35). However, no specific age group was seen in methadone poisoning. The duration of hospitalization and the time of referral to the emergency department to the death of the patient was significantly correlated with mortality in both the groups. The prevalence of intentional rice kill poising was greatest, effecting young population, we recommend that health care awareness program and training should be provided in this regard. Furthermore, psychiatric care should be made easily available in the region.

Phosphine on Venus Cannot Be Explained by Conventional Processes

The recent candidate detection of ∼1 ppb of phosphine in the middle atmosphere of Venus is so unexpected that it requires an exhaustive search for explanations of its origin. Phosphorus-containing species have not been modeled for Venus' atmosphere before, and our work represents the first attempt to model phosphorus species in the venusian atmosphere. We thoroughly explore the potential pathways of formation of phosphine in a venusian environment, including in the planet's atmosphere, cloud and haze layers, surface, and subsurface. We investigate gas reactions, geochemical reactions, photochemistry, and other nonequilibrium processes. None of these potential phosphine production pathways is sufficient to explain the presence of ppb phosphine levels on Venus. If PH₃'s presence in Venus' atmosphere is confirmed, it therefore is highly likely to be the result of a process not previously considered plausible for venusian conditions. The process could be unknown geochemistry, photochemistry, or even aerial microbial life, given that on Earth phosphine is exclusively associated with anthropogenic and biological sources. The detection of phosphine adds to the complexity of chemical processes in the venusian environment and motivates in situ follow-up sampling missions to Venus. Our analysis provides a template for investigation of phosphine as a biosignature on other worlds.

Antidotal effect of dihydroxyacetone against phosphine poisoning in mice

Phosphine (PH₃ ) is widely used as an insecticide and rodenticide. On the contrary, many cases of PH₃ poisoning have been reported worldwide. Unfortunately, there is no specific antidote against PH₃ toxicity. Disruption of mitochondrial function and energy metabolism is a well-known mechanism of PH₃ cytotoxicity. Dihydroxyacetone (DHA) is an adenosine triphosphate supplying agent which significantly improves mitochondrial function. The current study was designed to evaluate DHA's effect on inhalational PH₃ poisoning in an animal model. DHA was injected into BALB/c mice before and/or after the start of the PH₃ inhalation. The cytochrome c oxidase activity was assessed in the animals' brain, heart, and liver exposed to PH₃ (for 15, 30, and 60 min, with and without the antidote). The LC₅₀ of PH₃ was calculated to be 18.02 (15.42-20.55) ppm over 2 h of exposure. Pretreatment of DHA (1 or 2 g/kg) increased the LC₅₀ of PH₃ by about 1.6- or 3-fold, respectively. Posttreatment with DHA (2 g/kg) increased the LC₅₀ of PH₃ by about 1.4-fold. PH₃ inhibited the activity of cytochrome c oxidase in the assessed organs. It was found that DHA treatment restored mitochondrial cytochrome c oxidase activity. These findings suggested that DHA could be an effective antidote for PH₃ poisoning.

Rodenticide-induced acute liver failure - Uncommon presentation of commonly available poison

Rodenticide or 'rat poison' is easily available in a predominantly agrarian economy such as India. Metal phosphides or yellow phosphorous are two common rodenticides. Acute liver failure caused by accidental or suicidal poisoning with rodenticides has been infrequently reported in literature. Liver transplantation offers the best chances of survival in severe intoxication. However, the availability of liver transplantation in resource-limited settings presents a challenge. N-acetyl cysteine has been successfully used in paracetamol poisoning. Its use in rodenticide-induced acute liver failure is not so well known. We report three cases of rodenticide-related acute liver failure, one of them being a pregnant lady. All three patients were given N-acetyl cysteine and two patients improved. It is possible that the administration of N-acetyl cysteine contributed to the improvement in these two.

Acute aluminum phosphide poisoning: The menace of phosphine exposure

Aluminum phosphide (AlP) is a popular fumigant used widely for the safe storage of food grain. Although A1P is free from toxic residues, it releases phosphine which acts on mitochondrial components of almost all types of pests. Unfortunately A1P is also a common suicidal agent in developing countries with no known antidote. In addition, accidental exposure to phosphine may also occur. AlP poisoning affects cardiac and vascular tissue directly and can result in multiorgan system failure leading to death in severe cases. There is no specific biomarker for diagnosing AlP poisoning and management depends on a high level of clinical suspicion. Although acetylcholinesterase has been suggested as a surrogate biomarker of AlP exposure, there are opposing views. In this review, we analyzed the relevant published material with emphasis on the need to recognize and explore the use of plasma mitochondrial enzyme activity as a potential biomarker for AlP exposure.

Development of detection methods for the diagnosis and analysis of highly toxic metal phosphides: A comprehensive and critical review

Metal phosphides, especially aluminum phosphide, and phosphine (PH₃ ) are widely used as insecticides and rodenticides for protection of grains during process of storage and transportation. The main reason of poisoning with this compound is related to the conscious ingestion of salts or accidental inhalation of PH₃ . So the early and accurate diagnosis of poisoning can significantly help to the effective clinical treatment or recognition of death cause. PH₃ is somewhat unstable due to reaction with oxygen or hemoglobin leading to formation of oxy-acids phosphorous. Here, we critically reviewed the literature introducing the quantitative and qualitative methods for the detection of metal phosphides, PH₃ , and its products. This study obviously demonstrates that during past years, different diagnosis methods have been remarkably progressed. Head-space gas chromatography and confirmatory colorimetric methods have been as the most popular techniques. Also, the gas sensors are a promising method that must be more progressed.

Human Zinc Phosphide Exposure in Lebanon: A Case Report and Review of the Literature

Introduction

Toxicity from rodenticides such as metal phosphides is common worldwide, particularly in developing countries where consumers have access to unlabeled and uncontrolled insecticides and pesticides.

Case Report

We present the first documentation of a metal phosphide exposure in Lebanon. A middle-aged woman presented to the emergency department following the ingestion of an unknown rodenticide. Spectroscopy analysis of the sample brought by the patient was used and helped identify zinc phosphide. The patient developed mild gastrointestinal symptoms and was admitted to the intensive care unit for observation without further complications.

Review

We subsequently conducted a literature review to understand the diagnosis, pathophysiology, clinical presentation, and management of metal phosphide toxicity. Multiple searches were conducted on MEDLINE and PubMed, and articles related to the topics under discussion were included in the review. Metal phosphide is associated with significant morbidity and mortality involving all body systems. Patients presenting with metal phosphide intoxication need extensive workup including blood testing, electrocardiogram, and chest radiography. To date there is no antidote for metal phosphide toxicity, and management is mostly supportive. Many treatment modalities have been investigated to improve outcomes in patients presenting with metal phosphide toxicities.

Conclusion

Emergency physicians and toxicologists in developing countries need to consider zinc and aluminum phosphides on their differential when dealing with unlabeled rodenticide ingestion. Treatment is mostly supportive with close monitoring for sick patients. Further research is needed to better understand metal phosphide toxicity and to develop better treatment options.

Investigating the outcomes of aluminum phosphide poisoning in khorshid referral hospital, Isfahan, Iran: A retrospective study

Objective:

Aluminum phosphide (ALP) (rice-tablet) is a common cause of adult poisoning in Iran, including Isfahan. So far, no effective treatment has been identified for this poisoning. We aimed to investigate the outcome of ALP poisoned patients admitted to the clinical toxicology ward of Khorshid Hospital in Isfahan from 2017 to 2019.

Methods:

This chart-review study was performed on the population of ALP poisoned patients admitted to the clinical toxicology ward of Khorshid University Hospital from 2017 to 2019 treated with the hospital’s new treatment protocol, using the complete enumeration approach. The outcomes were determined by reviewing and abstracting medical charts of ALP poisoned patients from the hospital archive.

Findings:

The most common complaints at admission were depressed consciousness (41.9%) and vomiting (32.2%). There was no significant change in blood sugar, pH, base excess (BE), and venous blood bicarbonate throughout their hospitalization (P > 0.05). Treatment outcomes had a significant relationship with blood pH 2 h and 6 h after admission and the BE 6 h after admission (P < 0.05). There was also a significant relationship between the outcome and the length of stay, initial ejection fraction (EF), and EF in predischarge echocardiography (P < 0.05). Out of 31 patients, 24 (77.4%) died within 72 h, 5 (16.1%) recovered without any complication, and 2 (6.5%) recovered with some complications.

Conclusion:

The mortality rate of ALP poisoned patients was reasonably high and can be attributed to the poor efficacy of the new treatment protocol or the long time it takes for patients to reach the hospital and start receiving treatments.

Acute liver failure secondary to yellow phosphorus rodenticide poisoning: Outcomes at a center with dedicated liver intensive care and transplant unit

Accidental or suicidal poisoning with yellow phosphorus or metal phosphides (YPMP) such as aluminum (AlP) zinc phosphide (Zn3P2) commonly cause acute liver failure (ALF) and cardiotoxicity. These are used as household, agricultural and industrial rodenticides and in production of ammunitions, firecrackers and fertilizers. In absence of a clinically available laboratory test for diagnosis or toxin measurement or an antidote, managing their poisoning is challenging even at a tertiary care center with a dedicated liver intensive care unit (LICU) and liver transplant facility.

PATIENTS AND METHODS

Patients with YPMP related ALF were monitored using standardized clinical, hemodynamic, biochemical, metabolic, neurological, electrocardiography (ECG) and SOFA score and managed using uniform intensive care, treatment and transplant protocols in LICU. Socio-demographic characteristics, clinical and biochemical parameters and scores were summarized and compared between 3 groups i.e. spontaneous survivors, transplanted patients and non-survivors. Predictors of spontaneous survival and the need for liver transplant are also evaluated.

RESULTS

Nineteen patients with YPMP related ALF were about 32 years old (63.2% females) and presented to us at a median of 3 (0 - 10) days after poisoning. YPMP related cardiotoxicity was rapidly progressive and fatal whereas liver transplant was therapeutic for ALF. Spontaneous survivors had lower dose ingestion (<17.5 grams), absence of cardiotoxicity, < grade 3 HE, lactate < 5.8, SOFA score < 14.5, and increase in SOFA score by < 5.5. Patients with renal failure need for CVVHDF and KCC positivity on account of PT-INR > 6.5 had higher mortality risk. Patients undergoing liver transplant and with spontaneous recovery required longer ICU and hospital stay. At median follow-up of 3.4 (2.6 - 5.5) years, all spontaneous survivors and transplanted patients are well with normal liver function.

CONCLUSIONS

Early transfer to a specialized center, pre-emptive close monitoring, and intensive care and organ support with ventilation, CVVHDF, plasmapheresis and others may maximize their chances of spontaneous recovery, allow accurate prognostication and a timely liver transplant.

Successful management of zinc phosphide poisoning-a Hungarian case

BACKGROUND

Zinc phosphide (ZnP) is the basic component of several insecticides easily accessible worldwide. Intentional or accidental intoxication may lead to severe complications and multiple organ failure, resulting in high mortality. No known antidote is currently available. The iron-chelation and the antioxidative effects are well-known features of alpha-lipoic acid (ALA), although its use in the treatment of ZnP poisoning has not been documented previously. We describe the case of a patient with serious ZnP poisoning with multiple organ failure, where ALA was also included in the patient's supportive therapy.

CASE PRESENTATION

A 65-year-old man ingested 125 g of Arvalin® (containing 5 g ZnP) and presented to the Emergency Department, with respiratory insufficiency and decreased consciousness. He developed hypokalemia, hypocalcemia, low white blood cell count, elevated C-reactive protein level, mixed acidosis, hepatic and kidney damage, thickening of the jejunal wall, and lung atelectasis, which served as a basis for the ensuing bacterial pneumonia. Antibiotics and adequate supportive therapy were provided. Laboratory tests indicated liver damage (slightly increased liver enzymes, low pseudocholinesterase levels; 706 U/L on day 2), possibly caused by the patient's chronic alcoholism or the ZnP poison itself, therefore, hepatoprotective agents, ALA (Thiogamma Turbo-Set®) with N-acetylcysteine were administered for six consecutive days. Pseudocholinesterase values increased sixfold until the end of the second week of care. Fifteen days after admission, the patient was relocated to the department of psychiatry with stable vital functions, clear consciousness, declining inflammatory markers, and improved liver function. He was discharged 1 month later, fully recovered.

CONCLUSIONS

Our case is the first documented voluntary and severe ZnP poisoning in Hungary. Our patient developed multiple organ failure and atelectasis, possibly resulting in the observed respiratory infection. The development of bacterial pneumonia highlighted the dangers of phosphine-induced atelectasis. The use of ALA in our patient's case, as an antioxidant and agent for metal chelation, suggested that this agent could be a promising tool in the prevention and treatment of ZnP-induced hepatic damage.

Pathological changes induced by phosphine poisoning: a study on 8 children

Aluminum phosphide (ALP) has been extensively used as an economical and effective insecticide, rodenticide, and fumigant. The active ingredient of ALP is phosphine (PH₃), the use of which can lead to accidental inhalation and mass poisoning with high mortality. Exposure to PH₃ will give rise to global damage in the human body. This study reviewed 4 fatal accidents including 8 children with PH₃ poisoning and aimed to determine the pathological changes that resulted from exposure to PH₃ and, secondly, aimed to determine whether oxidative stress was involved in PH₃-induced neurotoxicity using histopathological and immunohistochemistry (IHC) methods. After focusing on the pathological changes on the major organs, we found severe damage induced by PH₃ in many systems, especially the neurological system, including neuronal, axonal, and vascular injuries as well as oxidative damage with increased expression of 4-hydroxy-2-trans-nonenal (4HNE), 8-hydroxy-2'-deoxyguanosine (8-OH-dG), and 3-nitrotyrosine (3-NT) in the brain, which indicated that oxidative stress was a crucial mechanism for neuronal death in PH₃ toxicity. Moreover, we observed severe myocardial and hepatocellular fatty degeneration in the tissues of the heart and liver. We considered that these characteristic changes are a suggestive sign of PH₃ poisoning and partly explained the toxic mechanism of PH₃ (inhibition of mitochondrial oxidative phosphorylation). We hope that this research could improve the understanding of the toxicity of PH₃ in both forensic and clinical practice.

Trivalent Phosphorus and Phosphines as Components of Biochemistry in Anoxic Environments

Phosphorus is an essential element for all life on Earth, yet trivalent phosphorus (e.g., in phosphines) appears to be almost completely absent from biology. Instead phosphorus is utilized by life almost exclusively as phosphate, apart from a small contingent of other pentavalent phosphorus compounds containing structurally similar chemical groups. In this work, we address four previously stated arguments as to why life does not explore trivalent phosphorus: (1) precedent (lack of confirmed instances of trivalent phosphorus in biochemicals suggests that life does not have the means to exploit this chemistry), (2) thermodynamic limitations (synthesizing trivalent phosphorus compounds is too energetically costly), (3) stability (phosphines are too reactive and readily oxidize in an oxygen (O₂)-rich atmosphere), and (4) toxicity (the trivalent phosphorus compounds are broadly toxic). We argue that the first two of these arguments are invalid, and the third and fourth arguments only apply to the O₂-rich environment of modern Earth. Specifically, both the reactivity and toxicity of phosphines are specific to aerobic life and strictly dependent on O₂-rich environment. We postulate that anaerobic life persisting in anoxic (O₂-free) environments may exploit trivalent phosphorus chemistry much more extensively. We review the production of trivalent phosphorus compounds by anaerobic organisms, including phosphine gas and an alkyl phosphine, phospholane. We suggest that the failure to find more such compounds in modern terrestrial life may be a result of the strong bias of the search for natural products toward aerobic organisms. We postulate that a more thorough identification of metabolites of the anaerobic biosphere could reveal many more trivalent phosphorus compounds. We conclude with a discussion of the implications of our work for the origin and early evolution of life, and suggest that trivalent phosphorus compounds could be valuable markers for both extraterrestrial life and the Shadow Biosphere on Earth.

Antidotal Action of Some Gold(I) Complexes toward Phosphine Toxicity

Phosphine (PH3) poisoning continues to be a serious problem worldwide, for which there is no antidote currently available. An invertebrate model for examining potential toxicants and their putative antidotes has been used to determine if a strategy of using Au(I) complexes as phosphine-scavenging compounds may be antidotally beneficial. When Galleria mellonella larvae (or wax worms) were subjected to phosphine exposures of 4300 (±700) ppm·min over a 20 min time span, they became immobile (paralyzed) for ∼35 min. The administration of Au(I) complexes auro-sodium bisthiosulfate (AuTS), aurothioglucose (AuTG), and sodium aurothiomalate (AuTM) 5 min prior to phosphine exposure resulted in a drastic reduction in the recovery time (0-4 min). When the putative antidotes were given 10 min after the phosphine exposure, all the antidotes were therapeutic, resulting in mean recovery times of 14, 17, and 19 min for AuTS, AuTG, and AuTM, respectively. Since AuTS proved to be the best therapeutic agent in the G. mellonella model, it was subsequently tested in mice using a behavioral assessment (pole-climbing test). Mice given AuTS (50 mg/kg) 5 min prior to a 3200 (±500) ppm·min phosphine exposure exhibited behavior comparable to mice not exposed to phosphine. However, when mice were given a therapeutic dose of AuTS (50 mg/kg) 1 min after a similar phosphine exposure, only a very modest improvement in performance was observed.

New environmental model for thermodynamic ecology of biological phosphine production

We present a new model for the biological production of phosphine (PH₃). Phosphine is found globally, in trace amounts, in the Earth's atmosphere. It has been suggested as a key molecule in the phosphorus cycle, linking atmospheric, lithospheric and biological phosphorus chemistry. Phosphine's production is strongly associated with marshes, swamps and other sites of anaerobic biology. However the mechanism of phosphine's biological production has remained controversial, because it has been believed that reduction of phosphate to phosphine is endergonic. In this paper we show through thermodynamic calculations that, in specific environments, the combined action of phosphate reducing and phosphite disproportionating bacteria can produce phosphine. Phosphate-reducing bacteria can capture energy from the reduction of phosphate to phosphite through coupling phosphate reduction to NADH oxidation. Our hypothesis describes how the phosphate chemistry in an environmental niche is coupled to phosphite generation in ground water, which in turn is coupled to the phosphine production in water and atmosphere, driven by a specific microbial ecology. Our hypothesis provides clear predictions on specific complex environments where biological phosphine production could be widespread. We propose tests of our hypothesis in fieldwork.

Rodenticide Poisoning

How to cite this article: D'Silva C, Krishna B. Rodenticide Poisoning. Indian J Crit Care Med 2019;23(Suppl 4):S272–S277.

Dihydroxyacetone as a definitive treatment for aluminium phosphide poisoning in rats

Aluminium phosphide (AlP), a very toxic pesticide also known as the rice tablet, releases phosphine gas upon contact with water, moisture, or gastric acid. Its mortality rate in humans is 70-100 % due to cardiogenic shock and refractory hypotension. Dihydroxyacetone (DHA) is a simple ketonic carbohydrate, mainly used for sunless skin tanning. It also plays a beneficial role in the treatment of hypotension and cardiogenic shock by restoring blood volume and cellular respiration. The aim of this study was to investigate the its effect on the haemodynamics and electrocardiogram (ECG) in male rats poisoned with AlP. The animals were divided into the following groups: control (received 1 mL corn oil, orally), AlP (received 15 mg kg-1 AlP solved in corn oil, orally), AlP plus DHA (treated with 50 mg kg-1 of DHA 30 min after receiving AlP), and AlP plus N-acetyl cysteine (NAC) (treated with 200 mg kg-1 of NAC 30 min after receiving AlP). The animals were then anaesthetised and ECG, blood pressure, and heart rate were recorded for 120 min. Treatment with AlP alone and in combination with NAC was associated with progressive hypotension, tachycardia, and ECG disturbances in rats, resulting in 100 % mortality 3 h after poisoning. However, DHA achieved 100 % survival in the poisoned rats and prevented AlP-induced ECG and haemodynamic abnormalities. The main mechanism of DHA in the treatment of AlP poisoning is unclear, but the findings suggest the promising therapeutic potential of DHA against AlP poisoning.

Antidotes for aluminum phosphide poisoning - An update

Aluminum phosphide (AlP), an inexpensive solid fumigant, is frequently used for grain conservation despite its alleged high toxicity. Increased utilization of AlP for agricultural and non-agricultural purposes during the last four decades has resulted in increment of AlP-attributed poisoning numbers. Moreover, due to its limitless accessibility in developing countries, AlP has been increasingly used for suicide. Moisture-exposed AlP undergoes a chemical reaction producing phosphine gas, which in turn inhibits cytochrome oxidase and impedes cellular oxygen consumption. Lethality remains elevated reaching rates of >50% and no effective antidote is available. Nevertheless, experimental and clinical studies suggested that magnesium sulfate, melatonin, N-acetylcysteine, glutathione, sodium selenite, vitamin C and E, triiodothyronine, liothyronine, vasopressin, milrinone, Laurus nobilis L., 6-aminonicotinamide, boric acid, acetyl-L-carnitine and coconut oil, may serve as antidotes by reducing the deleterious oxidative properties of AlP. This article reviews the afore-mentioned chemicals suggested to specifically treat AlP poisoning and discusses their protective mechanisms and main outcomes.

Phosphine Analysis in Postmortem Specimens Following Inhalation of Phosphine: Fatal Aluminum Phosphide Poisoning in Children

Phosphine is an insecticide for the fumigation of grains, animal feed, and leaf-stored tobacco, and it was used as a rodenticide in bulk grain stores. Phosphine poisoning may occur after accidental inhalation of phosphine, sometimes leading to death. Analysis of phosphine and its metabolites in postmortem specimens from seven fatal cases was conducted in this study, as well as postmortem specimens collected from rabbits exposed to phosphine. The total phosphine in postmortem specimens was analyzed by headspace gas chromatography coupled with mass spectrometry. Diagnosis of aluminum phosphide poisoning was made after postmortem toxicological analysis and confirmed by police investigation. The deaths of the children occurred after inhalation of phosphine generated from aluminum phosphide contacting moisture in the air in all seven fatal cases. The concentration of total phosphine in the biological fluids and tissues of victims ranged from 0.2 to 4.7 μg/mL (μg/g). Animal experiments demonstrated that the phosphine generated from aluminum phosphide could rapidly cause death. The toxicological analysis of postmortem specimens provides useful information in diagnosis of aluminum phosphide poisoning in forensic science. As an important fumigation pesticide, aluminum phosphide deserves special attention, especially since there is no specific antidote and there is a high fatality rate.

Aluminum phosphide poisoning: Successful recovery of multiorgan failure in a pediatric patient

Aluminum phosphide (AlP) is an insecticide and rodenticide that produces phosphine gas when exposed to moisture. Exposure to AIP has been described as through inhalation and ingestion routes and is typically either accidental or a suicidal attempt. The result is potential multiorgan toxicity involving the heart, kidneys, lungs, and liver, with an overall mortality related to exposure reported from 30% to 77%. The initial symptoms are nonspecific and can include epigastric pain, vomiting, diarrhea, dizziness, and dyspnea. Patients rapidly experience multisystem organ failure, cardiovascular collapse, and, finally, death. We report the case of a 3 year old girl with AlP poisoning who developed cardiogenic shock, ventricular arrhythmias, respiratory failure, liver injury, and significant acute kidney injury (AKI). She was successfully supported with veno-arterial extracorporeal membrane oxygenation (ECMO) for 16 days, treated with lidocaine and magnesium sulfate for ventricular arrhythmias, and received continuous renal replacement therapy (CRRT) and hemodialysis for 24 days for metabolic acidosis secondary to AKI. Despite her severe clinical presentation, she had complete normalization of her end-organ dysfunction with no neurological sequelae. This case demonstrates the high index of suspicion required for AlP poisoning given the potential for rapid progression and severe multiorgan toxicity. The authors recommend prompt referral to a tertiary care center with ECMO and CRRT capability in cases of suspected or documented AlP poisoning.

Aluminum phosphide poisoning in Saudi Arabia over a nine-year period

BACKGROUND

Aluminum phosphide (AlP) is an insecticide and rodenticide used to protect stored grains from rodents and other household pests. This substance is highly toxic to humans and has been the cause of many accidental and intentional deaths due in part to poor regulation of sales and distribution in many countries.

OBJECTIVES

Describe poisonings reported to the Ministry of Health in Saudi Arabia in terms of demographic variables and by time and geographic distribution.

DESIGN

Retrospective medical record review.

SETTING

Ministry of Health hospitals nationwide.

PATIENTS AND METHODS

Using a semi-structured checklist, data was collected from patient records that contained sociodemographic variables and the outcome (died or discharged).

MAIN OUTCOME MEASURES

Aggregated data, summary statistics and statistical comparisons.

SAMPLE SIZE

68 patients.

RESULTS

Thirty-eight (56%) were female and the mean (SD) age of patients was 18.6 (1.86) years. Eighteen of 22 (82%) patients who died were younger than 20 years old. Mortality in patients younger than 20 years of age was greater than in adults (P=.043). Mortality was highest in patients younger than 7 years of age (P=.006). The cases were reported by the Islamic years 1427-1435, corresponding approximately to Gregorian years 2006 to 2017. Fifty-six cases (83%) were reported from Jeddah. Most cases were due to accidental exposure to phosphine gas during fumigation.

CONCLUSION

Mortality due to AlP poisoning was highest in children and most commonly occurred during fumigation of households. Delays in medical attention and diagnosis may have contributed to mortality.

LIMITATIONS

Retrospective data collection and relatively small sample size. Data on exact amount and route of phosphide ingestion or exposure not available.

CONFLICT OF INTEREST

None.

Mortality from aluminum phosphide poisoning in Kermanshah Province, Iran: characteristics and predictive factors

OBJECTIVES

Aluminum phosphide (ALP), also known in Iran as rice tablets, is one of the most effective rodenticides used to protect stored grain. However, ALP poisoning regularly causes mortality in humans. The aim of this study was to evaluate the characteristics and predictive factors of mortality from ALP poisoning.

METHODS

This study evaluated all patients with ALP poisoning referred to Imam Khomeini Hospital in Kermanshah Province, Iran from 2014 to 2015. For each patient, the following information was recorded: age, sex, the number of tablets consumed, the number of suicide attempts, the time elapsed from consumption to treatment, blood pressure, blood pH, HCO3 levels, and PCO2 . Differences between the survivors and non-survivors of ALP poisoning were analyzed using univariate logistic regression and multivariate analysis.

RESULTS

In this study, 48 patients were male and 29 patients were female (total: 77 patients). The average age of the survivors and non-survivors was 28.7 and 31.3 years, respectively. All cases (100%) of ALP poisoning were intentional, with the goal of committing suicide. The main predictive variables of mortality from ALP poisoning were blood pressure, blood pH, and time elapsed from consumption to treatment.

CONCLUSIONS

The likelihood of mortality in patients with ALP poisoning can be predicted using blood pressure, blood pH, and time elapsed from consumption to treatment. These findings may help healthcare providers take more effective measures to treat patients with ALP poisoning.

Fresh red blood cells transfusion protects against aluminum phosphide-induced metabolic acidosis and mortality in rats

BACKGROUND

Aluminum phosphide (AlP) is used as pesticide in some countries for protection of stored grains. Human poisoning with AlP due to suicide attempt or accidental environmental exposure is associated with very high mortality partially due to development of severe metabolic acidosis. Previous studies have shown that hemoglobin has high buffering capacity and erythrocytes can potentially be used for management of metabolic acidosis. The aim of this study was to evaluate the effect of fresh packed red blood cells (RBC) transfusion on survival and cardiovascular function in AlP-poisoned rats.

METHODOLOGY/PRINCIPAL FINDINGS

Rats were poisoned with AlP by gavage. Fresh packed RBC was transfused via tail vein after AlP administration. Acid-base balance, vital signs and mortality was assessed and compared in experimental groups. Infusion of fresh packed RBC (1.5 ml) one hour after AlP (4-15 mg/kg) intoxication was associated with a significant decrease in mortality rate. Packed RBC infusion improved blood pH, HCO3-, Na+ and Ca2+ levels. Plasma troponin level was also reduced and ECG changes were reversed following packed RBC infusion in AlP intoxicated rats.

CONCLUSIONS

Our results showed that fresh RBC transfusion could ameliorate metabolic acidosis and enhance survival in AlP-poisoned rat. We assume that an increase in pool of RBCs may modulate acid-base balance or potentially chelate AlP-related toxic intermediates via phosphine-hemoglobin interaction.

Moringa oleifera extract (Lam) attenuates Aluminium phosphide-induced acute cardiac toxicity in rats

•

Aluminium phosphide (AlP) affects many organs especially heart.

•

Antioxidant activities of Moringa was investigated after acute AlP intoxication.

•

Moringa preventive effects were determined histopathologically.

•

Moringa significantly re-equilibrates antioxidant parameters back near to their normal values.

Background

Moringa oleifera extract (Lam) has many antioxidant and protective properties. Objective: to investigate the antioxidant activities of Lam in counteracting the high oxidative stress caused by acute sub-lethal aluminium phosphide (AlP) intoxication in rat heart. These activities will be detected by histopathological examination and some oxidative stress biomarkers.

Methods

a single sub-lethal dose of Alp (2 mg/kg body weight) was administered orally, and Lam was given orally at a dose (100 mg/kg body weight) one hour after receiving AlP to rats.

Results

aluminium phosphide caused significant cardiac histopathological changes with a significant increase in malondialdehyde (MDA); lipid peroxidation marker; and a significant depletion of antioxidant enzymes (catalase and glutathione reductase). However, treatment with Lam protected efficiently the cardiac tissue of intoxicated rats by increasing antioxidants levels with slight decreasing in MDA production compared to untreated group.

Conclusions

This study suggested that Moringa oleifera extract could possibly restore the altered cardiac histopathology and some antioxidant power in AlP intoxicated rats, and it could even be used as adjuvant therapy against AlP-induced cardiotoxicity.

Profile of aluminum phosphide poisoning in a tertiary care institute in the sub-Himalayan region

Context:

Aluminum phosphide (ALP) is a highly toxic agricultural fumigant pesticide commonly implicated in poisoning.

Aim:

The aim of the study was to study the profile of patients presenting with ALP poisoning in Dr. RPGMC Kangra, Tanda, Himachal Pradesh.

Settings and Design:

This was a retrospective study conducted in the Department of Medicine at Dr. RPGMC Kangra, Tanda, Himachal Pradesh, from August 2011 to January 2014.

Material and Methods:

Case record forms of 117 patients were reviewed and analyzed. Data were collected for sociodemographic and clinical parameters. Outcome of patients was recorded as expired and improved. All the patients were managed symptomatically.

Statistical Analysis:

Statistical analysis was performed using SPSS version 15. P < 0.05 was considered statistically significant.

Results:

Out of the total 117 patients included in the study, 61 (52.1%) were males and 56 (47.1%) were females. Mean age ± standard deviation of presentation was 30.9 ± 12.2 years. About 70% of the patients were from rural background. Out of the total 117 patients, 68 (58.1%) patients had expired and 49 (41.9%) had improved. Most of the patients in the expired group consumed ALP in tablet form (54.7% of the total). Nearly 57% of the patients had leukocytosis at presentation and <5% had leukopenia. The mean pulse rate and mean systolic blood pressure in the expired group were 116.24 ± 14.3 per minute and 89.9 ± 16.83 mmHg which was statistically significant. The mean change in creatinine value (ΔCr) in the expired group was 1.03 ± 0.36 which was statistically significant.

Conclusions:

The prognosis of the patients can be anticipated on assessing the cardiac status and mean change in creatinine value (ΔCr) at the time of admission.

Organophosphorus Xenobiotic Toxicology

Originally, organophosphorus (OP) toxicology consisted of acetylcholinesterase inhibition by insecticides and chemical threat agents acting as phosphorylating agents for serine in the catalytic triad, but this is no longer the case. Other serine hydrolases can be secondary OP targets, depending on the OP structure, and include neuropathy target esterase, lipases, and endocannabinoid hydrolases. The major OP herbicides are glyphosate and glufosinate, which act in plants but not animals to block aromatic amino acid and glutamine biosynthesis, respectively, with safety for crops conferred by their expression of herbicide-tolerant targets and detoxifying enzymes from bacteria. OP fungicides, pharmaceuticals including calcium retention agents, industrial chemicals, and cytochrome P450 inhibitors act by multiple noncholinergic mechanisms, often with high potency and specificity. One type of OP-containing fire retardant forms a highly toxic bicyclophosphate γ-aminobutyric acid receptor antagonist upon combustion. Some OPs are teratogenic, mutagenic, or carcinogenic by known mechanisms that can be avoided as researchers expand knowledge of OP chemistry and toxicology for future developments in bioregulation.

Yellow phosphorus-induced Brugada phenocopy

BACKGROUND

Metallic phosphides (of aluminum and phosphide) and yellow phosphorus are commonly used rodenticide compounds in developing countries. Toxicity of yellow phosphorus mostly pertains to the liver, kidney, heart, pancreas and the brain. Cardiotoxicity with associated Brugada ECG pattern has been reported only in poisoning with metallic phosphides.

METHODS AND RESULTS

Brugada phenocopy and hepatic dysfunction were observed in a 29-year-old male following yellow phosphorus consumption. He had both type 1 (day1) and type 2 (day2) Brugada patterns in the electrocardiogram, which resolved spontaneously by the third day without hemodynamic compromise.

CONCLUSION

Toxins such as aluminum and zinc phosphide have been reported to induce Brugada ECG patterns due to the generation of phosphine. We report the first case of yellow phosphorus-related Brugada phenocopy, without hemodynamic compromise or malignant arrhythmia.

Prevention of phosphine-induced cytotoxicity by nutrients in HepG2 cells

Background & objectives:

Phosphides used as an insecticide and rodenticide, produce phosphine (PH₃) which causes accidental and intentional poisoning cases and deaths. There is no specific treatment or antidote available for PH₃ poisoning. It is suggested that PH₃-induced toxicity is associated with adenosine triphosphate (ATP) depletion; therefore, in this study the effect of some nutrients was evaluated on PH₃ cytotoxicity in a cell culture model.

Methods:

PH₃ was generated from reaction of zinc phosphide (10 mM) with water in the closed culture medium of HepG2 cells, and cytotoxicity was measured after one and three hours of incubation. ATP, glutathione (GSH) and lipid peroxidation were also assessed at one or three hours post-incubation. ATP suppliers including dihydroxyacetone, glyceraldehyde and fructose were added to the culture medium 10 min before PH₃ generation to prevent or reduce phosphine-induced cytotoxicity.

Results:

Phosphine caused about 30 and 66 per cent cell death at one and three hours of incubation, respectively. ATP content of the cells was depleted to 14.7 per cent of control at one hour of incubation. ATP suppliers were able to prevent cytotoxicity and ATP depletion induced by PH₃. Dihydroxyacetone, α-ketoglutarate, fructose and mannitol restored the ATP content of the cells from 14.7 per cent to about 40, 34, 32 and 30 per cent, respectively. Lipid peroxidation and GSH depletion were not significantly induced by zinc phosphide in this study.

Interpretation & conclusions:

The results supported the hypothesis that phosphine-induced cytotoxicity was due to decrease of ATP levels. ATP suppliers could prevent its toxicity by generating ATP through glycolysis. α-keto compounds such as dihydroxyacetone and α-ketoglutarate may bind to phosphine and restore mitochondrial respiration.