Tricyclic antidepressant (TCA) overdose?,”TCA overdose can have central nervous system toxicity )eg, sedation, seizures, coma), anticholinergic toxicity (eg, hyperthermia, dilated pupils, intestinal ileus, urinary retention), and cardiac toxicity. Cardiac toxicity causes most death in TCA overdose. Sodium bicarb is used to treat cardiac toxicity, which is characterized by prolonged QRS duration and ventricular arrhythmias. Sodium bicarb increases serum pH and extracellular sodium
thereby alleviating the cardio-depressant action on sodium channels.”