Ketorolac tromethamine: an experimental study of its analgesic effects in the rat.

1. The formalin test and R-III nociceptive electromyographic reflex were used to determine the origin of analgesia induced by ketorolac tromethamine (KT) in rats. 2. The effects of KT and morphine were compared after i.v. administration. 3. Mepacrine and indomethacin were associated to KT to determine if prostaglandins are involved in the central action of KT. 4. In both tests KT had a poor analgesic effect without dose-response relationships. 5. A central component is involved in the analgesia produced by KT, but neither prostaglandins nor opioid receptors seem to mediate this effect.