Buprenorphine: a new potent long-acting synthetic analgesic. Comparison with morphine.

A new thebaine derivative, buprenorphine, 0.6 mg, was compared with morphine 15 mg in a double-blind trial, in patients recovering from elective Caesarean section. Within 1 h of administration analgesia was obtained with both drugs and was sustained for 7-8 h with buprenorphine, and 3-4 h with morphine. Buprenorphine caused a greater decrease in diastolic arterial pressure than did morphine, but arterial systolic pressure and heart rate were not influenced by either drug. No serious side-effects were encountered in this study.