Analgesic efficacy of ketorolac and morphine in neonatal rats

Ketorolac is a potent nonsteroidal antiinflammatory drug (NSAID). In adult humans and animals, its analgesic efficacy can be comparable to opiates. Ho wever, it has not been studied in neonatal animals. We conducted a blinded, controlled study comparing the effects of ketorolac and morphine in neonat al rats using the formalin model. Animals were given intraperitoneal (ip) i njections of ketorolac or morphine at 3 or 21 days of age. Ketorolac had an analgesic and antiinflammatory effect in 21-day-old pups, but not in the 3 -day-olds. Morphine had a significant analgesic, but no antiinflammatory ef fect at both ages. These results indicate that ketorolac is an effective an algesic agent in preweaning, but not neonatal rats. Opiates may be more app ropriate analgesics in neonates. (C) 2001 Elsevier Science Inc. All rights reserved.