THE ANTINOCICEPTIVE EFFECT OF S-(-IBUPROFEN IN RABBITS - EPIDURAL VERSUS INTRAVENOUS ADMINISTRATION())

This study was designed to determine whether systemic absorption plays any role in the antinociceptive effect of epidural (EP) sodium S(+)-i buprofen (IB). One week after surgical implantation of EP catheters, s ix rabbits were given EP injections with either normal saline (NS) 0.4 mL or TB 10 mg in 0.4 mL NS (Group 1) on separate days. Each animal w as injected with IB 10 mg intravenously (IV) on another day. Six contr ol rabbits (Group 2) had neither surgery nor any injection. Analgesic testing was performed using electric stimulation through two electroca rdiogram (EGG) skin electrodes with built-in adhesive, attached to sha ved hip areas using 50 V, 1 Hz, 3 ms, before and 0.5, 1, 2, and 3 h af ter injection in Group 1, and in similar times in controls. The 95% co nfidence intervals (CI) of the mean difference between baseline and ma ximal nociceptive response latency of all groups were compared using a nalysis of covariance (ANCOVA) adjusted for baseline measurements. Thi s comparison covered all possible pairs among all groups. Significant antinociceptive effects were seen after EP IB but not after control or TV IB. Neither motor dysfunction nor evidence of systemic toxicity or neurotoxicity was observed in any animal.