Which electrolyte abnormalities are characteristic of digoxin toxicity?

Which electrolyte abnormalities are characteristic of digoxin toxicity?

• A. I only
• B. II only
• C. I, II
• D. II, III

Answer: (C)

Digoxin toxicity disrupts ion balance by inhibiting the Na+/K+-ATPase pump in heart cells. This causes potassium to shift out of cells, raising extracellular potassium levels, so hyperkalemia is a characteristic lab finding of digoxin overdose. Magnesium also plays a role: low magnesium (hypomagnesemia) can predispose to toxicity and worsen its effects because Mg helps modulate the pump and cellular excitability; when Mg is low, digoxin binds more readily and toxicity increases. So the pattern you’re looking for involves elevated potassium along with low magnesium.

Digoxin toxicity disrupts ion balance by inhibiting the Na+/K+-ATPase pump in heart cells. This causes potassium to shift out of cells, raising extracellular potassium levels, so hyperkalemia is a characteristic lab finding of digoxin overdose. Magnesium also plays a role: low magnesium (hypomagnesemia) can predispose to toxicity and worsen its effects because Mg helps modulate the pump and cellular excitability; when Mg is low, digoxin binds more readily and toxicity increases. So the pattern you’re looking for involves elevated potassium along with low magnesium.