A comparison of pre- and post-surgical administration of bupivacaine or buprenorphine following laparotomy in the rat

The effects of bupivacaine, a long-acting local anaesthetic, and buprenorph ine, an opioid analgesic, administered either pre- or post-operatively, wer e investigated in a rat laparotomy model. Surgical anaesthesia was induced and maintained with halothane. The type of analgesic treatment was a signif icant factor in the reduction in body weight and food and water intake whic h occurred following surgery. The largest reductions were seen in the bupiv acaine-treated groups and those animals which received no analgesics. The t iming of administration of analgesics had no influence on the effect of bup ivacaine administration. The group receiving buprenorphine before surgery s howed less depression in food intake than the group receiving buprenorphine at the end of surgery. Animals which received buprenorphine showed less de pression of activity than these receiving saline or bupivacaine.