The effect of spinal ibuprofen on opioid withdrawal in the rat

This study examines the effect of spinal ibuprofen on the behavioral manife stations associated with the opioid abstinence syndrome. Rats (n = 8 per gr oup) were infused for 5 days with morphine and then pretreated with a spina l bolus dose of ibuprofen before systemic naloxone antagonism (300 mu g). G roups included ibuprofen S(+) 1.36, 13.6, and 136 nmol, and ibuprofen R(-) 136 nmol. A separate group of saline-infused rats was given ibuprofen S(+) 136 nmol, before naloxone antagonism. Ibuprofen S(+), but not R(-), dose-de pendently and stereospecifically blocked opioid withdrawal hyperalgesia but did not significantly alter other signs of the opioid abstinence syndrome. We conclude that hyperalgesia associated with opioid withdrawal can be blo cked by spinally administered ibuprofen, and suggest that there may be a ro le for spinal prostaglandins in the enhancement of nociception observed in association with the opioid abstinence syndrome.