Final answer:
The nurse should assess serum potassium before the administration of digoxin and furosemide as these medications can affect potassium levels in the body.
Step-by-step explanation:
The nurse should assess serum potassium before the administration of digoxin (Lanoxin) and furosemide (Lasix). Both medications can affect potassium levels in the body. Digoxin can increase serum potassium levels, while furosemide can decrease serum potassium levels. It is important to ensure that the patient's potassium level is within the normal range to prevent complications.