The nurse is preparing to administer digoxin (Lanoxin) to a client experiencing atrial fibrillation. Which of the following electrolyte imbalances would the nurse assess to reduce the incidence of toxicity with digoxin (Lanoxin)?

Rationale: Hypokalemia increases digoxin toxicity risk as both drugs compete for binding sites on sodium-potassium ATPase pump in the heart. Low potassium levels potentiate digoxin's effects, leading to toxicity. A nurse should monitor potassium levels to prevent adverse effects.
Summary of incorrect choices:
B: Hypophosphatemia does not directly affect digoxin toxicity risk.
C: Hypocalcemia does not impact digoxin toxicity.
D: Hypernatremia is not associated with increased digoxin toxicity.