Serial intravenous doses of dezocine, morphine, and nalbuphine in the management of postoperative pain for outpatients.

Adult patients who had arthroscopic surgery under general anesthesia and requested postoperative pain relief were randomized to receive treatment in a double-blind protocol with 5 mg of intravenous dezocine (20 patients), morphine (22 patients), nalbuphine (18 patients), or saline (24 patients). At 10-min intervals, starting with the first dose of analgesic, patients could choose up to three additional doses of the primary treatment, or choose an alternative analgesic if the primary drug was unsatisfactory. One to four doses of morphine were given as the alternate treatment if the initial treatment was dezocine or nalbuphine, and one to four doses of dezocine were given if the initial treatment was saline or morphine. The proportion of patients treated successfully by the initial treatments (i.e., not requesting alternate treatment), with P value for difference from placebo treatment, were saline 25%, nalbuphine 33% (P = 0.048), morphine 54% (P = 0.04), and dezocine 75% (P = 0.003). Dezocine and morphine are more efficacious than nalbuphine in the management of early postoperative pain. As an alternate analgesic in this study, dezocine required fewer doses to achieve patient satisfaction and was thus more efficacious than morphine. The incidence of treatment-related, adverse effects was different from that of saline or other treatments only for nalbuphine-related pain or burning on injection and dezocine-related facial itching. With respect to analgesic actions and side effects, dezocine seems more like morphine than nalbuphine.