Which electrolyte abnormality is most strongly linked to digoxin toxicity risk?

Which electrolyte abnormality is most strongly linked to digoxin toxicity risk?

• A. Hyperkalemia
• B. Hypokalemia
• C. Hypocalcemia
• D. Hypermagnesemia

Answer: (B)

Low potassium levels raise the risk of digoxin toxicity because digoxin binds to the same Na+/K+-ATPase pump site as potassium. When potassium is scarce, there are more available sites for digoxin to bind, so the drug inhibits the pump more strongly. This increases intracellular calcium and the likelihood of dangerous arrhythmias, making toxicity more likely even at digoxin levels that might be tolerated with normal potassium. Hyperkalemia is often a consequence of digoxin toxicity rather than a predisposing factor, while hypocalcemia or hypermagnesemia don’t have as direct and strong a link to toxicity risk.

Low potassium levels raise the risk of digoxin toxicity because digoxin binds to the same Na+/K+-ATPase pump site as potassium. When potassium is scarce, there are more available sites for digoxin to bind, so the drug inhibits the pump more strongly. This increases intracellular calcium and the likelihood of dangerous arrhythmias, making toxicity more likely even at digoxin levels that might be tolerated with normal potassium. Hyperkalemia is often a consequence of digoxin toxicity rather than a predisposing factor, while hypocalcemia or hypermagnesemia don’t have as direct and strong a link to toxicity risk.