Atypical Presentation of an Organophosphorus Poisoning

Abstract

Organophosphorus (OP) insecticide self-poisoning is a major global health problem, with approximately 200,000 deaths each year. A 25 year old woman was transported to an emergency department for altered mental status. On physical examination, the patient appeared alert but not responsive. She vomited once prior to arrival in the ED, but otherwise had no muscarinic manifestations during her hospital course. It was later determined that she had intentionally ingested Orthene, a fireant killer made up of 50% acephate. Acephate is one of the few commercially available, over-the-counter organophosphorus insecticides in the United States. This patient had an erythrocyte cholinesterase level of 1957 IU/L (9572-15031) and serum cholinesterase of 164 IU/L (2673-6592). She was treated with intravenous pralidoxime and transferred to psychiatry after two days at which time her physical examination, including mental status, was normal. This case is unusual due to the paucity of muscarinic manifestations and clinicians need to be aware that this can occur.