title: Intentional self-poisoning with the chlorophenoxy herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA).
abstract: OBJECTIVE
  Data on poisoning with MCPA (4-chloro-2-methyl-phenoxyacetic acid) are limited to 6 case reports. Our objective is to describe outcomes from intentional self-poisoning with MCPA in a prospective case series of 181 patients presenting to hospitals in Sri Lanka.
  
  
  METHODS
  Patient information was collected by on-site study physicians as part of an ongoing prospective cohort study of poisoned patients. Medical history, clinical details, and blood samples were obtained prospectively.
  
  
  RESULTS
  Overall clinical toxicity was minimal in 85% of patients, including mild gastrointestinal symptoms in 44% of patients. More severe clinical signs of chlorophenoxy poisoning reported previously, such as rhabdomyolysis, renal dysfunction, and coma, also occurred but were uncommon. Eight patients died (4.4%). Most deaths occurred suddenly from cardiorespiratory arrest within 48 hours of poisoning; the pathophysiological mechanism of death was not apparent. The correlation between admission plasma MCPA concentration and clinical markers of severity of toxicity (physical signs, symptoms, and increased creatine kinase level) was poor.
  
  
  CONCLUSIONS
  Intentional self-poisoning with MCPA generally causes mild toxicity, but cardiorespiratory arrest and death may occur. All patients should receive routine resuscitation and supportive care. It seems reasonable to correct acidosis and maintain an adequate urine output, but there is insufficient evidence to support other specific interventions. Our data do not support a clinical role for measurement of plasma MCPA in the acute management of poisoning, and insufficient data were available to fully examine the utility of measured electrolytes and creatine kinase levels.
authors.affiliation: South Asian Clinical Toxicology Research Collaboration, Medical School, Australian National University, Acton, Australian Capital Territory, Australia. dmroberts@iprimus.com.au
authors.forename: Darren M
authors.initials: DM
authors.lastname: Roberts
authors.forename: Ruwan
authors.initials: R
authors.lastname: Seneviratne
authors.forename: Fahim
authors.initials: F
authors.lastname: Mohammed
authors.forename: Renu
authors.initials: R
authors.lastname: Patel
authors.forename: Lalith
authors.initials: L
authors.lastname: Senarathna
authors.forename: Ariyasena
authors.initials: A
authors.lastname: Hittarage
authors.forename: Nick A
authors.initials: NA
authors.lastname: Buckley
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Dawson
authors.forename: Michael
authors.initials: M
authors.lastname: Eddleston
mesh_terms: D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000097:blood / Q000506:poisoning*; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003402:Creatine Kinase / Q000097:blood; D004635:Emergency Medicine / Q000379:methods; D005260:Female; D006540:Herbicides / Q000097:blood / Q000506:poisoning*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011041:Poisoning / Q000097:blood / Q000628:therapy; D011446:Prospective Studies; D013188:Sri Lanka; D013406:Suicide, Attempted; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; D006540:Herbicides; D008456:2-Methyl-4-chlorophenoxyacetic Acid; D003402:Creatine Kinase