Tricyclic Antidepressant Toxicity Clinical Presentation

Updated: Jan 26, 2023
  • Author: Vivian Tsai, MD, MPH, FACEP; Chief Editor: David Vearrier, MD, MPH  more...
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History of suicidal ideation, prior suicide attempts, circumstances around ingestion, intended cyclic antidepressant (CA) usage, co-ingestants, time of ingestion, and dose ingested should be obtained from the patient directly and also from the patient's family.

CA exposure in children is common. The potentially lethal dose (with desipramine, imipramine, or amitriptyline) is as low as 15 mg/kg. Toddlers can exceed this threshold with only 1-2 pills and should be evaluated in the emergency department. [5]

Onset of symptoms typically occurs within 2 hours of ingestion, which corresponds to the peak CA serum level, which may range from 2-12 hours.

Determining which specific CA is involved may be helpful. Although amoxapine is associated with a higher incidence of seizures, maprotiline causes more severe cardiac toxicity.

Cardiovascular manifestations may include the following:

  • Palpitation
  • Chest pain
  • Hypotension

Central nervous system manifestations may include the following:

  • Convulsion
  • Decrease mental status
  • Respiratory depression
  • Drowsiness
  • Coma

Peripheral autonomic system manifestations may include the following:

  • Dry mouth
  • Dry skin
  • Urinary retention
  • Blurred vision

Physical Examination

Physical findings are usually consistent with the anticholinergic toxidrome and quinidine-like cardiotoxicity, and may include the following:

  • Tachycardia
  • Hypotension and orthostasis
  • Fever
  • Altered mental status
  • Ileus
  • Absent bowel sounds
  • Rigidity
  • Dry skin and mucous membranes
  • Mydriasis