Analysis of amitriptyline overdose in emergency medicine

Amitriptyline is a tricyclic antidepressant. In general, toxicity effects develop within 30 min of overdose and peak from 2 h to 6 h. Anticholinergic effects predominate in cases of low dose ingestion. In cases of high dose ingestion, marked depression of the central nervous system is coupled with cardiotoxicity, seizures and hypotension.

Amitriptyline-intoxicated patients admitted to the emergency department (ED) of Dicle University Hospital were evaluated between January 2005 and April 2007. Social and demographic status, clinical and laboratory findings, treatments and outcomes were recorded. Age, sex, marital status, time of hospital admission, consciousness levels, ECG findings, requirement for respiratory support, follow-up periods and antidepressant overdose risk assessment (ADORA) criteria were analysed using SPSS software.

A total of 110 cases of overdose by amitriptyline was evaluated. Suicide attempts by amitriptyline overdose in adult single women were the commonest finding. The commonest symptoms seen during initial examinations were sinus tachycardia (66.3%), altered mental state (78.1%) and hypotension (7.3%). Mechanical ventilatory support was required in 9.1% of cases. Most patients (n=76, 69.1%) were treated in the ED (p=0.001). 60 (54.5%) patients were discharged from the ED within 24 h after admission (p<0.0001).

Most of the patients were young single women. Altered mental state and tachycardia were the commonest symptoms. The initial symptoms of amytriptyline overdose patients may be life threatening, but effective supportive treatments were helpful. There was high correlation between ADORA criteria and the dose ingested.