Final answer:
The priority action for a client reporting weakness and heart fluttering while on furosemide and digoxin is to withhold the next dose of digoxin and assess for digoxin toxicity.
Step-by-step explanation:
When a client taking furosemide and digoxin for exacerbation of heart failure reports symptoms such as weakness and heart fluttering, the priority action by the nurse should be to withhold the next dose of digoxin. These symptoms could be indicative of digoxin toxicity, which can be life-threatening and requires immediate medical attention. Furosemide can cause electrolyte imbalances that may exacerbate digoxin toxicity, making it crucial for the nurse to assess the patient's electrolyte levels, particularly potassium, and the digoxin level. Administering a higher dose of furosemide or altering fluid intake without further assessment could be harmful.