Which antidote is used for tricyclic antidepressant overdose?

• A. Activated Charcoal
• B. Sodium Bicarbonate
• C. Glucose
• D. Physostigmine

Answer: (B)

The main idea is countering the heart’s sodium-channel blockade seen in tricyclic antidepressant overdose. Sodium bicarbonate is the best antidote because it serves two helpful roles at once: it raises the blood (and urine) pH and it provides a sodium load. The added sodium helps overcome the drug’s blockade of fast sodium channels in the heart, improving conduction and reducing the risk of dangerous wide-complex rhythms. The higher pH also helps stabilize cardiac conduction during toxicity. This approach can lessen arrhythmias and support hemodynamics.

Activated charcoal can be useful for decontamination if the ingestion was recent, but it isn’t an antidote. Glucose is not an antidote for TCA toxicity, though it’s used if hypoglycemia is present. Physostigmine is not used here and can be dangerous in TCA overdose, as it may provoke seizures or serious arrhythmias and does not reverse the toxicity.