Antidotal effect of dihydroxyacetone against phosphine poisoning in mice

The possible therapeutic role of intravenous lipid emulsion in acute aluminium phosphide poisoning: a randomized controlled clinical trial

Introduction

Aluminum phosphide (ALP) is a highly toxic rodenticide and the mortality rates caused by it have been demonstrated up to 70-100% in various studies. Unfortunately, there is no specific antidote to manage its toxic effects. This study aimed to assess the biochemical and clinical efficacy and safety of intravenous lipid emulsion as an adjuvant therapy in acute aluminum phosphide poisoning.

Patients and methods

Sixty-four cases with acute ALP poisoning were stratified according to severity by the Poison Severity Score into severe and moderate groups (32 patients each). Patients were then randomly allocated into either receiving intravenous lipid emulsion in addition to the conventional treatment or receiving the conventional treatment only by using block randomization.

Results

Treatment by ILE resulted in a significant improvement in the survival time, the mean arterial blood pressure, arterial blood gases, and a significant reduction in serum lactate levels. The need for intubation and mechanical ventilation was insignificantly lower in the intervention groups compared to control groups. However, the reduction in mortality rate in the patients of intervention groups compared with control groups was found to be non-significant. Intravenous lipid emulsion use in acute ALP poisoning significantly prolonged the survival time, improved the metabolic acidosis, decreased the serum lactate levels and increased the mean arterial blood pressure and hospital stay in the intervention groups. And insignificantly decreased the mortality rate, need of intubation and mechanical ventilation, and the total dose of vasopressors.

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 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.

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.