A double-blind comparison between fentanyl and buprenorphrine in analgesic-supplemented anaesthesia.

Buprenorphine 0.3 mg or fentanyl 0.125 mg i.v. were used to supplement nitrous oxide anaesthesia in a double-blind investigation of 40 patients undergoing major abdominal surgery. Initially both narcotics appeared to suppress tachycardia and increased arterial pressure in response to surgery, but 80% of the patients who received fentanyl eventually required a further supplement of halothane 0.5%, whereas no patient who received buprenorphine required halothane. Recovery from anaesthesia was similar in both groups, but the duration of analgesia after operation was significantly greater after buprenorphine than after fentanyl.