Methemoglobinemia and Seizure Following Indoxacarb Poisoning

ABSTRACT

Indoxacarb is an oxadiazine insecticide with selective lethality through blockade of neuronal voltage-dependent sodium channels. It has a low mammalian toxicity, and few cases of human toxicity after indoxacarb ingestion can be found in the literature. A 36 year-old male patient visited our ED after a generalized tonic clonic seizure, which was witnessed by his mother. His past medical history was nonspecific. On initial presentation, he showed a decreased level of consciousness with a Glasgow coma score of 5/15 (E1V1M3), unprotected airway, hypoxia, and cyanosis. The saturation gap and cyanosis after intubation and mechanical ventilation was strongly suggestive of methemoglobinemia due to poisoning. Finally, the methemogobin (metHb) level was 27.4%. Therefore, the patient received 100 mg of methylene blue (2 mg/kg, 1% solution) and 50 g of charcoal. The insecticide was found to be ingested xenobiotic (Steward Gold(R); 5% indoxacarb; 95% inert ingredients and other components). On the second hospital day, the patient became alert. The patient's metHb level was 0.1%. The endotracheal tube was removed. On the fifth hospital day, he was discharged in good condition. Herein we present a case of indoxacarb poisoning with methemoglobiemia and seizure, which are unusual presentations.