Before administering digoxin to a patient with influenza and chronic heart failure, what should the nurse assess?

Before administering digoxin to a patient with influenza and chronic heart failure, what should the nurse assess?

• A. Prothrombin time
• B. Urine specific gravity
• C. Serum potassium level
• D. Hemoglobin and hematocrit

Answer: (C)

Potassium level is the key factor in digoxin safety. Digoxin works by inhibiting the Na+/K+-ATPase pump, and low potassium increases digoxin binding to that pump, heightening its effects. That makes toxicity more likely, even if the digoxin level is within the normal range. An influenza illness can cause vomiting, diarrhea, and reduced intake, which may drop potassium and raise the risk of toxicity, so checking the serum potassium before administration is essential. The other tests aren’t as directly related to digoxin safety: prothrombin time isn’t impacted by digoxin, urine specific gravity reflects hydration rather than digoxin risk, and hemoglobin/hematocrit don’t influence digoxin’s safety. If potassium is low, correct it and reassess before giving digoxin, monitoring for potential toxicity symptoms and rhythm changes.

Potassium level is the key factor in digoxin safety. Digoxin works by inhibiting the Na+/K+-ATPase pump, and low potassium increases digoxin binding to that pump, heightening its effects. That makes toxicity more likely, even if the digoxin level is within the normal range. An influenza illness can cause vomiting, diarrhea, and reduced intake, which may drop potassium and raise the risk of toxicity, so checking the serum potassium before administration is essential. The other tests aren’t as directly related to digoxin safety: prothrombin time isn’t impacted by digoxin, urine specific gravity reflects hydration rather than digoxin risk, and hemoglobin/hematocrit don’t influence digoxin’s safety. If potassium is low, correct it and reassess before giving digoxin, monitoring for potential toxicity symptoms and rhythm changes.