KETOROLAC CAUSES THE RELEASE OF METHIONINE-ENKEPHALIN IN RATS

Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) that is ind icated for the short-term management of moderately severe, acute pain, that causes analgesia equivalent to that caused by morphine. It has b een shown experimentally that the analgesia produced by ketorolac in m ice can be diminished by pretreatment with naloxone. This observation suggests that ketorolac produces some of its analgesia by interacting with opioid receptors. However, ketorolac does not directly interact w ith opioid receptors (Lopez et al., 1987). The present experiments dem onstrate that the analgesia produced by ketorolac may be caused by the release of the endogenous opioid, methionine-enkephalin.