A patient on digoxin presents with nausea, visual halos, and bidirectional ventricular tachycardia. Hypokalemia is noted on labs. Which electrolyte abnormality primarily potentiates digoxin toxicity?
- A Hyperkalemia
- B Hypocalcemia
- C Hypomagnesemia
- D Hypokalemia ✓
Correct answer: D. Hypokalemia
Explanation
Hypokalemia potentiates digoxin toxicity because digoxin and potassium compete for the same binding site on the Na+/K+ ATPase pump. Low extracellular potassium allows more digoxin to bind, exacerbating pump inhibition and increasing the risk of life-threatening arrhythmias like bidirectional ventricular tachycardia.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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