title: Significant toxicity in a young female after low-dose tricyclic antidepressant ingestion.
abstract: BACKGROUND
  Tricyclic antidepressant (TCA) ingestions are a relatively common pediatric ingestion, with significant potential for both cardiac and neurological toxicity. Previous studies on pediatric TCA ingestions have found the threshold of toxicity to be 5 mg/kg.
  
  
  METHODS
  We report a case of an 8-year-old girl who presented to the emergency department with depressed mental status and seizure-like movements. An extensive workup was pursued to evaluate the cause of her mental status, which only revealed a positive urine toxicology screen for TCA. Quantified serum levels of amitriptyline were 121 ng/mL (therapeutic range, 50-300 ng/mL) and nortriptyline were 79 ng/mL (therapeutic range 70-170 ng/mL), 18 hours after onset of symptoms. Subsequent history obtained after her mental status returned to normal revealed that she had ingested amitriptyline at a dose of 0.8 mg/kg.
  
  
  CONCLUSIONS
  Tricyclic antidepressant ingestion has a high potential for toxicity in pediatric patients. This case suggests, contrary to previous literature, that toxicity may occur even with small doses.
authors.affiliation: Stanford/Kaiser Emergency Medicine Residency, Stanford, CA, USA. caseygrover@gmail.com
authors.forename: Casey A
authors.initials: CA
authors.lastname: Grover
authors.forename: Brian
authors.initials: B
authors.lastname: Flaherty
authors.forename: Derrick
authors.initials: D
authors.lastname: Lung
authors.forename: Natalie M
authors.initials: NM
authors.lastname: Pageler
mesh_terms: D000284:Administration, Oral; D000639:Amitriptyline / Q000008:administration & dosage / Q000506:poisoning* / Q000652:urine; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000506:poisoning* / Q000652:urine; D002648:Child; D003863:Depression / Q000139:chemically induced* / Q000175:diagnosis / Q000652:urine; D003937:Diagnosis, Differential; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D014218:Triage / Q000379:methods*; D016482:Urinalysis
chemical_list: D000929:Antidepressive Agents, Tricyclic; D000639:Amitriptyline