Tricyclic overdose treatment

• A. Naloxone
• B. Sodium Bicarbonate
• C. Flumazenil
• D. Activated Charcoal

Answer: (B)

In tricyclic antidepressant overdose, the heart’s fast sodium channels are blocked, causing slowed conduction and dangerous arrhythmias with a widened QRS. The treatment that directly counters this effect is intravenous sodium bicarbonate. Providing a sodium load helps overcome the sodium channel blockade, and alkalinizing the serum reduces the drug’s ability to affect the channels, which stabilizes conduction and narrows the QRS. You initiate it with a bolus dose and may repeat as needed, aiming for a pH around 7.45–7.55 and close monitoring of ECG and electrolytes.

Activated charcoal can be useful for ongoing decontamination if ingestion was recent, but it doesn’t reverse the cardiac toxicity. Naloxone and flumazenil do not address tricyclic toxicity and can worsen outcomes (seizures or other complications). In short, sodium bicarbonate specifically targets the dangerous cardiac effects of TCAs and is the primary treatment choice.