A patient who has had abdominal surgery has been receiving morphine sulfate via patient-controlled analgesia (PCA) pump. The nurse assesses the patient and notes that the patient's pupils are dilated, and that the patient is drowsy and lethargic. The patient's heart rate is 84 beats/minute, the respiratory rate is 10s breaths per minute, and the blood pressure is 90/50 mm Hg. What will the nurse do?