In suspected TCA overdose, what is the recommended treatment?

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Multiple Choice

In suspected TCA overdose, what is the recommended treatment?

Sodium bicarbonate is the treatment of choice because TCA overdose causes dangerous sodium-channel blockade in the heart, leading to widened QRS, arrhythmias, and hypotension. Giving sodium bicarbonate both provides a sodium load to overcome the channel blockade and alkalinizes the serum, which reduces the free fraction of the drug that can block cardiac sodium channels. This dual effect helps stabilize conduction and improve hemodynamics. The typical approach is to administer a bolus of 1 mEq/kg IV, and repeats may be given as needed to narrow the QRS and achieve a pH in the roughly normal to mildly alkalemic range, all with close ECG and hemodynamic monitoring. Flumazenil isn’t indicated because benzodiazepine reversal doesn’t address the sodium-channel–mediated cardiotoxicity and can provoke seizures in TCA overdose. Narcan targets opioid effects and won’t counteract TCA toxicity. Calcium chloride isn’t the standard rescue therapy for this specific mechanism and doesn’t reliably reverse the sodium-channel blockade, whereas bicarbonate directly targets the underlying problem.

Sodium bicarbonate is the treatment of choice because TCA overdose causes dangerous sodium-channel blockade in the heart, leading to widened QRS, arrhythmias, and hypotension. Giving sodium bicarbonate both provides a sodium load to overcome the channel blockade and alkalinizes the serum, which reduces the free fraction of the drug that can block cardiac sodium channels. This dual effect helps stabilize conduction and improve hemodynamics. The typical approach is to administer a bolus of 1 mEq/kg IV, and repeats may be given as needed to narrow the QRS and achieve a pH in the roughly normal to mildly alkalemic range, all with close ECG and hemodynamic monitoring.

Flumazenil isn’t indicated because benzodiazepine reversal doesn’t address the sodium-channel–mediated cardiotoxicity and can provoke seizures in TCA overdose. Narcan targets opioid effects and won’t counteract TCA toxicity. Calcium chloride isn’t the standard rescue therapy for this specific mechanism and doesn’t reliably reverse the sodium-channel blockade, whereas bicarbonate directly targets the underlying problem.

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