38. Which of the following is Wrong? (A) Opioids activate central μ opioid receptor which causing decreased peristalsis, decreased intestinal secretions, and increased sphincter tone. (B) Pain act as a physiologic antagonist to respiratory depression. (C) Up to two-thirds of patients experience nausea or vomiting during initiation of opioid therapy. (D) Antihistamines, opioid antagonists, propofol and ondansetron have been used for the treatment of pruritus.