What is the dosage of Sodium Bicarbonate for Tricyclic antidepressant overdose?

• A. 0.5 mEq/kg IV/IO
• B. 1 mEq/kg IV/IO
• C. 0.1 mEq/kg IV/IO
• D. 2 mEq/kg IV/IO

Answer: (B)

In tricyclic antidepressant overdose, the heart’s sodium channels are inhibited, leading to slowed conduction and widened QRS. Sodium bicarbonate helps by two actions: it increases serum pH (alkalinization) and raises extracellular sodium, both of which reduce the drug’s blocking effect on sodium channels and improve conduction. The standard initial treatment is a rapid bolus of 1 mEq/kg of sodium bicarbonate given IV or IO (using 8.4% solution, which provides 1 mEq per mL). If the QRS remains widened after the bolus, additional boluses can be given and then a continuous infusion is used to maintain alkalinization and sodium load, guided by rhythm and pH.