What should be monitored closely in a client receiving digoxin?

Monitoring serum potassium levels in a client receiving digoxin is critical due to the drug's narrow therapeutic index and its potential for causing toxicity. Digoxin works by increasing the force of cardiac contraction, which can be adversely affected by electrolyte imbalances, particularly potassium. An elevated serum potassium level (hyperkalemia) can decrease the effectiveness of digoxin, while a low serum potassium level (hypokalemia) increases the risk of digoxin toxicity, potentially leading to severe cardiac arrhythmias and other life-threatening complications.

Therefore, maintaining potassium levels within the normal range is essential for the safe use of digoxin therapy. Regular checks help healthcare providers adjust dosages appropriately and mitigate risks associated with electrolyte disturbances, ensuring effective and safe management of the client’s condition. The other options, while important in their own contexts, do not directly address the primary concern related to digoxin therapy as effectively as potassium monitoring does.