title: Intermediate syndrome after malathion ingestion despite continuous infusion of pralidoxime.
abstract: A 33-year-old female ingested an unknown quantity of malathion in a suicide attempt. Cholinergic signs consistent with severe organ, phosphate intoxication developed and were treated within 6 hours of ingestion. Intravenous atropine and a continuous infusion of pralidoxime (400 mg/h) were administered. Prolonged depression of plasma and red blood cell cholinesterases were documented. Despite an initial clinical improvement and the presence of plasma pralidoxime concentrations exceeding 4 microg/mL, the patient developed profound motor paralysis consistent with the diagnosis of Intermediate Syndrome. In addition to the dose and frequency of pralidoxime administration, other factors including persistence of organophosphate in the body, the chemical structure of the ingested organophosphate, and the time elapsed between ingestion and treatment may limit the effectiveness of pralidoxime as an antidote in organophosphate ingestions. This case study suggests that these factors should be taken into account in assessing the risk of Intermediate Syndrome after intentional organophosphate ingestions.
authors.affiliation: Veterans Administration Medical Center, Oregon Health Science University, Oregon Poison Center, Portland 97201-3098, USA. sudakind@ohsu.edu
authors.forename: D L
authors.initials: DL
authors.lastname: Sudakin
authors.forename: M E
authors.initials: ME
authors.lastname: Mullins
authors.forename: B Z
authors.initials: BZ
authors.lastname: Horowitz
authors.forename: V
authors.initials: V
authors.lastname: Abshier
authors.forename: L
authors.initials: L
authors.lastname: Letzig
mesh_terms: D000328:Adult; D000931:Antidotes / Q000627:therapeutic use*; D002800:Cholinesterase Inhibitors / Q000506:poisoning*; D002801:Cholinesterase Reactivators / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007306:Insecticides / Q000506:poisoning*; D008294:Malathion / Q000506:poisoning*; D010243:Paralysis / Q000139:chemically induced*; D011220:Pralidoxime Compounds / Q000627:therapeutic use*; D013577:Syndrome
chemical_list: D000931:Antidotes; D002800:Cholinesterase Inhibitors; D002801:Cholinesterase Reactivators; D007306:Insecticides; D011220:Pralidoxime Compounds; C028797:pralidoxime; D008294:Malathion