Managing tricyclic antidepressant overdose.

Tricyclic antidepressant overdose is the most common cause of death from prescription drugs. Clinical presentation of overdose from the tricyclic agents includes cardiac arrhythmias, hypotension, seizures, coma and anticholinergic signs such as hyperthermia, flushing and intestinal ileus. The highly toxic/lethal level (greater than 1,000 ng per mL) is manifested on electrocardiograms as prolongation of the QRS interval to 100 milliseconds or more. Treatment includes establishment of an airway, proper oxygenation and ventilation, fluid replacement at maintenance levels, cardiac monitoring, gastric lavage and charcoal administration, alkalinization to a blood pH of 7.5 with intravenous sodium bicarbonate, supportive therapy and continued cardiac monitoring after clinical recovery.