The Synergistic Antinociceptive Interactions of Endomorphin-1 with Dexmedetomidine and/or S(+)-Ketamine in Rats

Abstract

The coadministration of the N-methyl-D-aspartate antagonist receptor antagonist, S(+)-ketamine, or the specific alpha2-adrenoceptor agonist, dexmedetomidine, significantly enhances the antinociceptive effect of the endogenous mu-opioid agonist, endomorphin-1, at the spinal level. The triple combination of the three drugs causes a further improved antinociception.