A nurse is reinforcing teaching with a newly licensed nurse about monitoring morphine patient-controlled analgesia (PCA). Which of the following information should the nurse include?

"Using morphine PCA increases the client's risk of toxicity.”

"Diarrhea is an adverse effect of morphine PCA.”

"Check the client's pain level every 8 hours.”

"Instruct the client's visitors not to operate the PCA pump.”