42. Which of the following statement about tramadol is wrong?
(A) Oral tramadol has high bioavailability in the range of 80~90%.
(B) Tramadol has good efficacy for neuropathic pain and fibromyalgia.
(C) The risk for respiratory depression is lower than morphine at equianalgisic doses.
(D) Nausea and vomiting seldom occur in patients with tramadol.
(E) The tramadol is affected by cytochrome P450 2D6 activity.