Acute tricyclic antidepressant (TCA) poisoning is a potentially lethal intoxication that is characterized by life-threatening arrhythmias (sinus tachycardias, premature ventricular contractions, ventricular arrhythmias), anticholinergic toxidrome (mydriasis, dry mucous membrane, tachycardia, hypertension), central nervous system toxicity (lethargy, coma, myoclonic jerks), refractory hypotension, and sudden death.