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Tricyclic antidepressant overdose with sodium-channel blockade — SCE Acute Medicine MCQ

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ModerateToxicology and OverdoseTricyclic antidepressant overdose with sodium-channel blockadeSCE Acute Medicine

A 28-year-old man is brought in after a tricyclic antidepressant overdose. He is agitated, BP 86/50 mmHg, QRS duration is 160 ms and he has recurrent broad-complex tachycardia. What is the most appropriate next step in management?

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Correct answer: BGive intravenous sodium bicarbonate

TCA overdose with hypotension, broad QRS and ventricular arrhythmia is treated with IV sodium bicarbonate to overcome sodium-channel blockade. Amiodarone and beta-blockade may worsen conduction and hypotension. Flumazenil does not treat TCA toxicity and may provoke seizures if mixed overdose is present. The ECG QRS duration is a key severity marker.

Reference: TOXBASE tricyclic antidepressant poisoning, BNF