Prolonged clinical effects in modified-release amitriptyline poisoning.
BACKGROUND
Tricyclic antidepressant poisoning is often associated with significant cardiovascular and central nervous system toxicity. Effective treatment includes the use of appropriate gastric decontamination techniques, the administration of sodium bicarbonate, and meticulous supportive care. Tricylcic antidepressant toxicity typically lasts 24-48 hours following a significant overdose.


METHODS
We describe a case of tricyclic antidepressant poisoning where significant clinical toxicity (QRS prolongation, metabolic acidosis) was observed for up to 4 days following ingestion of a modified-release preparation of amitriptyline. Successful patient recovery was associated with the use of multidose activated charcoal and repeated administration of intravenous sodium bicarbonate.


CONCLUSIONS
Clinicians should be aware of the potential for prolonged tricyclic toxicity in patients who have ingested modified-release amitriptyline in overdose. Gastric decontamination techniques such as multidose activated charcoal and whole bowel irrigation should be considered where there is evidence of ongoing tricyclic antidepressant absorption or clinical toxicity following ingestion of a modified-release preparation. These interventions may be indicated for prolonged periods (greater than 36 hours) post ingestion.
O'Connor
Niall
N
Emergency Department, Guys and St. Thomas' NHS Trust, London, UK. Niall.OConnor@maile.hse.ie
Greene
Shaun
S
Dargan
Paul
P
Wyncoll
Duncan
D
Jones
Alison
A
D000138:Acidosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D000328:Adult; D000639:Amitriptyline / Q000493:pharmacokinetics / Q000506:poisoning*; D000929:Antidepressive Agents, Tricyclic / Q000493:pharmacokinetics / Q000506:poisoning*; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D002493:Central Nervous System Diseases / Q000139:chemically induced / Q000503:physiopathology; D002606:Charcoal / Q000627:therapeutic use; D003692:Delayed-Action Preparations / Q000506:poisoning; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D011041:Poisoning / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D017693:Sodium Bicarbonate / Q000008:administration & dosage / Q000627:therapeutic use; D016896:Treatment Outcome
D000929:Antidepressive Agents, Tricyclic; D003692:Delayed-Action Preparations; D002606:Charcoal; D000639:Amitriptyline; D017693:Sodium Bicarbonate