Question

A client who is receiving digoxin daily has a serum potassium level of 3 mEq/L (3 mmol/L) and is complaining of anorexia. The health care provider prescribes a serum digoxin level to be done. The nurse checks the results and should expect to note which level that is outside of the therapeutic range?

Answer 1

The nurse should expect to find a digoxin level outside the therapeutic range of 0.5-2.0 ng/mL, potentially indicating toxicity, especially since the patient's serum potassium level is low (hypokalemia), which can enhance digoxin's effects.

Step-by-step explanation:

A client who is receiving digoxin and has a serum potassium level of 3 mEq/L is at risk of exhibiting digoxin toxicity because normal potassium levels are integral to its safe therapeutic action. The normal therapeutic range for serum digoxin concentration is typically between 0.5 and 2.0 ng/mL. Given that hypokalemia (low potassium levels) can enhance the effects of digoxin and increase the risk of toxicity, a digoxin level outside the therapeutic range could be either below 0.5 ng/mL or, more concerningly, above 2.0 ng/mL when serum potassium is decreased.

Symptoms such as anorexia, nausea, or visual disturbances might indicate elevated digoxin levels, thus making it crucial for the healthcare provider to monitor these signs alongside the lab results. When potassium levels are decreased, this can alter the effect of digoxin on the heart, which is why maintaining a balanced serum potassium is critical when administering digoxin, and adjustments to the digoxin dose or potassium supplements might be necessary.