Ventilatory and Analgesic Effects of Dezocine in Humans

Publisher Website
Google Scholar
Abstract
The respiratory depressant and analgesic effects of i.v. dezocine were evaluated in 6 healthy volunteers. Single 0.15 mg/kg doses were compared with identical amounts of morphine, and the 2 drugs were given in combination. Five successive 0.15 mg/kg doses of dezocine also were given to identify dose-effect relationships. Respiratory center sensitivity was monitored by CO2 rebreathing and mouth occlusion pressure (P0.1) measurements, while analgesia to experimental pain was tested with submaximal tourniquet ischemia. Single 0.15 mg/kg doses of dezocine produced significantly more tolerance to experimental pain and greater respiratory depression than a comparable dose of morphine in the 1st h, but effects of both drugs were similar thereafter. Multiple doses of dezocine progressively increased pain tolerance from 46 .+-. 14% above control with the 1st dose to 70 .+-. 18% above control with the 2nd dose (cumulative total 0.30 mg/kg). Additional dezocine doses did not result in significantly more analgesia. Depression of CO2 sensitivity followed a similar pattern. Morphine 0.15 mg/kg, when given to subjects who had received a prior dose of dezocine, produced no additional effect beyond that observed with dezocine. With the reverse sequence, dezocine increased the respiratory depression of morphine but also produced a dramatic increment in analgesia, which suggested an additive action. Dezocine is therefore an effective analgesic with morphine-like effects. In humans it appears to be a slightly more potent analgesic than morphine in identical clinical doses (0.15 mg/kg). Dezocine is similar to other agonist-antagonist analgesics in that it exhibits a ceiling effect for respiratory depression that parallels its analgesic activity.