A 70-year-old woman on digoxin and furosemide for HFrEF presents with nausea, confusion, and bigeminy on ECG. Serum potassium is 2.8 mEq/L and digoxin level is markedly elevated. Which is the most appropriate immediate treatment?

• A IV potassium chloride alone
• B IV amiodarone infusion
• C Oral cholestyramine to bind enteric digoxin
• D Digoxin-specific antibody Fab fragments ✓

Explanation

Life-threatening digoxin toxicity with arrhythmia is treated with digoxin immune Fab, which binds free digoxin and is renally cleared. Hypokalemia from loop diuretics potentiates toxicity because low extracellular potassium permits greater digoxin binding to Na+/K+-ATPase. Potassium repletion alone (option A) does not address established severe toxicity, and amiodarone can worsen levels by displacing digoxin from tissue binding sites. Fab therapy is definitive.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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