An 80-year-old woman on digoxin and furosemide presents with nausea, yellow-tinged vision, and a pulse of 42 with frequent premature beats. Serum potassium is 3.0 mEq/L. The most appropriate immediate therapy is:

• A IV potassium chloride infusion alone
• B Digoxin-specific antibody (Fab) fragments ✓
• C Atropine followed by temporary pacing
• D Amiodarone loading dose IV

Explanation

Life-threatening digoxin toxicity with significant bradyarrhythmia or ventricular ectopy is treated with digoxin-specific Fab fragments, which bind free digoxin and reverse toxicity within minutes. Hypokalemia from furosemide sensitises the Na+/K+-ATPase and precipitates toxicity, so potassium is corrected alongside, but potassium alone cannot rescue established poisoning and may worsen AV block. Atropine and pacing are temporising measures. Amiodarone can add to bradycardia and interacts with digoxin.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.