N albuphine is an opioid against -antagonist of the phenanthrene series .related to naloxone and oxymorphone. It is claimed to produce good analgesia with fewer side effects than morphine (Wandless, 1987). The analgesic potency of nalbuphine is equal to that of morphine on a milligram basis (Fragen and Caldwell, 1977). The respiratory depressant capacity of intravenous nalbuphine a potent analgesic of the narcotic antagonist type and morphine were compared by Romagnoli and Keats, (1980) and they concluded that nalbuphine in increments to a total of 60mg/kg, doses in excess of 30 mg/kg failed to increase respiratory depression beyond that induced by morphine 20 mg/kg. A ceiling effect for respiratory depression previously known to exist only for nalorphine was thereby demonstrated to apply to nalbuphine.