A 74-year-old man on digoxin and furosemide presents with nausea, confusion, and reports yellow-green visual halos. ECG shows frequent premature ventricular complexes and runs of bidirectional ventricular tachycardia. Serum potassium is 2.8 mEq/L and serum creatinine is elevated. Along with potassium repletion, the definitive antidote is:
- A Digoxin-specific antibody Fab fragments ✓
- B Lidocaine bolus followed by infusion
- C Magnesium sulfate infusion alone
- D Phenytoin intravenously
Correct answer: A. Digoxin-specific antibody Fab fragments
Explanation
Xanthopsia, gastrointestinal symptoms, and bidirectional VT are features of severe digoxin toxicity, aggravated here by hypokalemia and renal impairment. Digoxin immune Fab binds free digoxin and reverses life-threatening arrhythmias within minutes, and is the definitive treatment. Magnesium suppresses some digitalis arrhythmias but does not remove the drug, and lidocaine or phenytoin are only temporizing measures when Fab is unavailable.
Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.