A nurse is caring for a client who has congestive heart failure and is taking digoxin daily. The client refused breakfast and is complaining of nausea and weakness. Which of the following actions should the nurse take first?

A. A dietitian consult may be helpful later, but it is not the first priority when the client is exhibiting symptoms that could be related to digoxin toxicity. B. An antiemetic might be considered later, but first, it is important to assess the client's overall condition to determine whether the nausea and weakness are related to digoxin toxicity. C. Resting might be helpful, but assessing vital signs is the most urgent step to determine whether the client has any cardiovascular instability, which could be related to digoxin toxicity. D. Checking the client's vital signs is the most important first step in assessing the client's condition. Nausea and weakness could be signs of digoxin toxicity, so the nurse must assess the client's heart rate, blood pressure, and other vital signs to guide further action.