Acute poisoning with emamectin benzoate.
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.


METHODS
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.
Yen
Tzung-Hai
TH
Division of Clinical Toxicology, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University School of Medicine, Taipei, Taiwan, Republic of China.
Lin
Ja-Liang
JL
D000368:Aged; D001772:Blood Cell Count; D001774:Blood Chemical Analysis; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007306:Insecticides / Q000506:poisoning*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000506:poisoning*; D008111:Liver Function Tests; D008297:Male; D013406:Suicide, Attempted
D007306:Insecticides; D007559:Ivermectin; C108024:emamectin benzoate