Granados-Soto V, Flores-Murrieta F J, Castañeda-Hernández G, Hong E, López-Muñoz F J
Departamento de Farmacología y Toxicología del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México DF, México.
J Pharm Pharmacol. 1995 Jun;47(6):514-7. doi: 10.1111/j.2042-7158.1995.tb05841.x.
The possibility that activation of opioid receptors is involved in the analgesic activity of ketorolac was explored. The analgesic effects of ketorolac, of ketocyclazocine, the prototype kappa-agonist, and of morphine, the prototype mu-agonist, were assayed in the pain-induced functional impairment model in the rat. All three drugs induced a significant analgesic effect in this model. Naloxone was able to antagonize the effects of ketocyclazocine and morphine. However, the effect of ketorolac was not blocked by naloxone, although a high dose, 3.2 mg kg-1, capable of blocking kappa-receptors was used. It is concluded that activation of mu- or kappa-opioid receptors, by either a direct or an indirect mechanism, does not play a role in the analgesic activity of ketorolac.
