Acute Poisoning with Emamectin Benzoate

Abstract

Background: Emamectin benzoate is the 4′‐deoxy‐4′‐epi‐methyl‐amino benzoate salt of avermectin B₁ (abamectin), which is similar structurally to natural fermentation products of Streptomyces avermitilis. Emamectin benzoate is being developed as a newer broad‐spectrum insecticide for vegetables and has a very low application rate. The mechanism of action involves stimulation of high‐affinity GABA receptors and a consequent increase in membrane chloride ion permeability. Animal studies indicate a wide margin of safety because mammalian species are much less sensitive due to lower GABA receptor affinities and relative impermeability of the blood‐brain barrier. Notably, the literature has not reported human exposure resulting in toxicity. Case Report: This paper describes a case of acute poisoning with Proclaim insecticide (Syngenta, Taiwan), consisting of 2.15% w/w emamectin benzoate in 2, 6‐bis (1, 1‐dimethylethyl)‐4‐methyl‐phenol and 1‐hexanol. The clinical manifestation was transient gastrointestinal upset with endoscopy‐proven gastric erosion and superficial gastritis, mild central nervous system depression, and aspiration pneumonia. No specific antidote exists for emamectin benzoate intoxication; this patient was treated successfully with gastric lavage, administration of activated charcoal, and empiric antibiotics. Drugs that enhance GABA activity such as barbiturates and benzodiazepines were avoided.

Keywords :

• Emamectin benzoate
• 2, 6‐bis (1, 1‐dimethylethyl)‐4‐methyl‐phenol
• Butylated hydroxy toluene
• 1‐hexanol
• Acute poisoning