sodium-nitrite and Vomiting

Intramuscular (IM) injection of nitrite (1-10 mg/kg) confers survival benefit and protects against lung injury after exposure to chlorine gas in preclinical models. Herein, we evaluated safety/toxicity parameters after single, and repeated (once daily for 7 days) IM injection of nitrite in male and female Sprague Dawley rats and Beagle dogs. The repeat dose studies were performed in compliance with the Federal Drug Administration's (FDA) Good Laboratory Practices Code of Federal Regulations (21 CFR Part 58). Parameters evaluated consisted of survival, clinical observations, body weights, clinical pathology, plasma drug levels, methemoglobin and macroscopic and microscopic pathology. In rats and dogs, single doses of ≥100 mg/kg and 60 mg/kg resulted in death and moribundity, while repeated administration of ≤30 or ≤ 10 mg/kg/day, respectively, was well tolerated. Therefore, the maximum tolerated dose following repeated administration in rats and dogs were determined to be 30 mg/kg/day and 10 mg/kg/day, respectively. Effects at doses below the maximum tolerated dose (MTD) were limited to emesis (in dogs only) and methemoglobinemia (in both species) with clinical signs (e.g. blue discoloration of lips) being dose-dependent, transient and reversible. These signs were not considered adverse, therefore the No Observed Adverse Effect Level (NOAEL) for both rats and dogs was 10 mg/kg/day in males (highest dose tested for dogs), and 3 mg/kg/day in females. Toxicokinetic assessment of plasma nitrite showed no difference between male and females, with C

Topics: Animals; Antidotes; Dogs; Dose-Response Relationship, Drug; Female; Injections, Intramuscular; Male; Maximum Tolerated Dose; Methemoglobinemia; No-Observed-Adverse-Effect Level; Rats, Sprague-Dawley; Risk Assessment; Sex Factors; Sodium Nitrite; Species Specificity; Toxicity Tests; Toxicokinetics; Vomiting

An acute and orally delivered toxic bait containing micro-encapsulated sodium nitrite (MESN), is under development to provide a novel and humane technology to help curtail damage caused by invasive wild pigs (Sus scrofa). We evaluated potential secondary risks for non-target species by: testing whether four different types of micro-encapsulation coatings could reduce vomiting by invasive wild pigs, testing the levels of residual sodium nitrite (SN) in tissues of invasive wild pigs, testing the environmental persistence of SN in vomitus, and conducting a risk assessment for scavengers.. Micro-encapsulation coatings did not affect the frequency of vomiting. We identified no risk of secondary poisoning for non-target scavengers that consume muscle, eyes, and livers of invasive wild pig carcasses because residual SN from the toxic bait was not detected in those tissues. The risk of secondary poisoning from consuming vomitus appeared low because ∼90% of the SN was metabolized or broken down prior to vomiting, and continued to degrade after being exposed to the environment. Secondary poisoning could occur for common scavengers that consume approximately ≥15% of their daily dietary requirements of digestive tract tissues or undigested bait from carcasses of invasive wild pigs in a rapid, single-feeding event. The likelihood of this occurring in a natural setting is unknown. The digestive tracts of poisoned invasive wild pigs contained an average of ∼4.35 mg/g of residual SN.. Data from this study suggest no risks of secondary poisoning for non-target species (including humans) that consume muscle, liver, or eyes of invasive wild pigs poisoned with a MESN toxic bait. More species-specific testing for scavengers that consume digestive tract tissues and undigested bait is needed to reduce uncertainty about these potential risks. © 2017 Society of Chemical Industry.

Topics: Animals; Animals, Wild; Female; Male; Pest Control; Poisoning; Sodium Nitrite; Sus scrofa; Vomiting

Methemoglobinemia is an unusual and potentially fatal condition in which hemoglobin is oxidized to methemoglobin and loses its ability to bind and transport oxygen. The most common cause of methemoglobinemia is the ingestion or inhalation of oxidizing agents such as nitrates or nitrites (e.g., sodium nitrite, which is used commonly as a preservative in curing meats and fish). This report summarizes the investigation of an incident of methemoglobinemia in five members of a household in New York who became ill after eating a meal seasoned with a white crystalline substance from a plastic bag labeled "Refined Iodized Table Salt" (Figure). The findings underscore the need for proper storage of hazardous materials to avoid unintentional ingestion and the importance of collaboration by multiple agencies to address a potential public health emergency.

Topics: Adult; Cyanosis; Dizziness; Enzyme Inhibitors; Female; Food Labeling; Food Preservatives; Humans; Male; Methemoglobin; Methemoglobinemia; Methylene Blue; Middle Aged; New York; Respiratory Insufficiency; Seizures; Sodium Chloride, Dietary; Sodium Nitrite; Unconsciousness; Vomiting