Which statement regarding electrolyte imbalances and digoxin is true?

The statement that hypercalcemia can increase digoxin toxicity is accurate because elevated calcium levels can enhance the effects of digoxin on the heart. Digoxin works by inhibiting the sodium-potassium ATPase pump, leading to an increase in intracellular calcium concentrations, which improves contractility. However, when calcium levels are already elevated (hypercalcemia), this can lead to an excessive increase in intracellular calcium, resulting in heightened toxicity and a greater risk of cardiac arrhythmias.

Patients taking digoxin need careful monitoring of their electrolyte levels, especially potassium and calcium, because imbalances can significantly affect heart function and increase the risk of serious side effects. Understanding the impact of these electrolytes is crucial for managing patients on digoxin therapy effectively.