What is the specific antidote for Tricyclic Antidepressant (TCA) poisoning?

In cases of Tricyclic Antidepressant (TCA) poisoning, sodium bicarbonate is the specific antidote because it can help to address the cardiotoxic effects associated with this type of overdose. TCAs can lead to severe cardiac complications such as arrhythmias and conduction disturbances, particularly by causing sodium channel blockade. By administering sodium bicarbonate, the extracellular sodium concentration is increased, which can help counteract the cardiotoxic effects. Additionally, sodium bicarbonate can also correct metabolic acidosis, which may arise during the overdose.

Other options do not serve as antidotes for TCA poisoning. For instance, digoxin immune Fab is used specifically for digoxin toxicity, while N-acetylcysteine is an antidote for acetaminophen poisoning. Flumazenil is a benzodiazepine antagonist used in cases of benzodiazepine overdose but can precipitate seizures in patients with TCA toxicity. Thus, sodium bicarbonate is the primary treatment choice in managing TCA poisoning due to its protective effect on the heart and its ability to correct acidosis.