One of the most intriguing developments in the field of narcotic analgesics has been the discovery of the narcotic antagonists.(1–3) These compounds, which reverse or prevent most of the pharmacological actions of the narcotic analgesics, may have analgesic activity themselves. This finding was uncovered serendipitously in the clinic with nalorphine(4) and was unexpected since this compound was essentially devoid of analgesic activity in the common animal test procedures then in use.(5–7) The importance of this finding lies in the fact that the narcotic-antagonist analgesics have a much lessened abuse potential. They do not produce a typical morphine-like physical dependence.(2, 3)