title: Comparison of oral and i.v. acetylcysteine in the treatment of acetaminophen poisoning.
abstract: OBJECTIVE
  The efficacy, safety, and cost issues that should be considered when deciding on the appropriate route of acetylcysteine for the treatment of patients with acetaminophen poisoning are reviewed.
  
  
  CONCLUSIONS
  Oral and i.v. acetylcysteine appear to be equally effective when given within 8-10 hours of acetaminophen overdose. Anaphylactoid reactions to i.v. acetylcysteine have generally been reported in 3-6% of acetaminophen-poisoned patients. Dosing errors and hyponatremia have occurred in pediatric patients receiving i.v. acetylcysteine. Several investigators found an increased rate of anaphylactoid reactions in patients treated with i.v. acetylcysteine whose pretreatment serum acetaminophen levels were nontoxic. Compounding i.v. acetylcysteine from the oral preparation is less expensive than using premade i.v. solution. State pharmacy laws dictate whether extemporaneous compounding of acetylcysteine from the oral formulation is allowed. Oral acetylcysteine administration has resulted in minimal anaphylactoid reactions and is safer than i.v. acetylcysteine. Oral therapy should preferentially be considered in patients with asthma or atopic histories. The most important factors to consider when selecting the route of acetylcysteine administration include individual susceptibility, the severity of acetaminophen toxicity, and the time interval between acetaminophen ingestion and initiation of acetylcysteine therapy.
  
  
  CONCLUSIONS
  Oral acetylcysteine administered within 8-10 hours of acetaminophen overdose prevents liver toxicity in the majority of patients who tolerate it and have no contraindications to therapy. I.V. acetylcysteine should be administered when patients are treated more than 10 hours postingestion of acetaminophen overdose or have underlying conditions preventing oral treatment. Anaphylactoid reactions are rare and occur more frequently in patients treated with the i.v. preparation.
authors.affiliation: Toxikon Consortium, Section of Clinical Toxicology, Division of Occupational Medicine, Cook County Hospital, 1900 West Polk Street, Suite 500, Chicago, IL 60612, USA. nkanter@aol.com
authors.forename: Michele Zell
authors.initials: MZ
authors.lastname: Kanter
mesh_terms: D000082:Acetaminophen / Q000506:poisoning*; D000111:Acetylcysteine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000284:Administration, Oral; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000506:poisoning*; D000707:Anaphylaxis / Q000139:chemically induced; D000931:Antidotes / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D062787:Drug Overdose; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D011247:Pregnancy
chemical_list: D018712:Analgesics, Non-Narcotic; D000931:Antidotes; D000082:Acetaminophen; D000111:Acetylcysteine