A nurse is reinforcing teaching with a client who has COPD and has been taking long-term high doses of prednisone. Which of the following instructions should the nurse include in the teaching?

“Limit potassium-containing foods in your diet.”

"Withhold prednisone for 48 hours prior to receiving contrast dye.”

"Measure your blood glucose levels periodically.”

"Take prednisone on an empty stomach."