Comparison of buprenorphine, pethidine and pentazocine for the relief of pain after operation.

The analgesic effects of buprenorphine 2 microgram/kg--1 and 8 microgram. kg--1 were compared with those of pethidine 1 mg. kg--1 and pentazocine 0.6 mg.kg--1 in 172 patients recovering from surgery. The drugs were given by i.m. injection in the period immediately after operation and the quality of pain relief was assessed at intervals for at least 4h. Buprenorphine 4-8 microgram-kg-1 was shown to be an effective analgesic, superior in some cases to the other drugs in the doses employed in the study.