Aripiprazole effect on prolongation of morphine antinociception effect

dopamine D2 and serotonin-1A (5-hydroxytryptamine, 5-HT1A) receptors with minimal side effects. Based on typical antipsychotic pharmacological profile, including antinociception effect and disruption opioid anti-nociceptive tolerance, the activity of Aripiprazole and its interaction with morphine on nociception was studied in the mouse tail flick and hot plate assay. Materials and methods: In experiment 1, mice received aripiprazole (5, 10 and 20 mg/kg IP), saline (1 ml/kg, IP) and morphine (5 mg/kg, IP) 30 minutes prior to the test. The tail flick and hot-plate methods were used for pain evaluation. In order to assess the effect of aripiprazole on morphine antinociception in experiment 2, it was administered 30 min after morphine injection and then the test was assessed. Comparisons between the groups were carried out using the Analysis of Variance (ANOVA), and post hoc Tukey's test. P<0.05 was considered to represent a significant difference. Results: The results indicated that aripiprazole at doses that had no affected themselves (10–20 mg/kg), accelerated and prolonged the morphine antinociceptive effect. It was also shown that partial agonist properties of D2 and 5-HT1A as well as antagonist properties of 5-HT2A in aripiprazole likely account for the potentiation of morphine antinociception. Conclusion: These findings also suggest that aripiprazole might have therapeutic value in combination to morphine as an adjuvant analgesic

Keywords:

Aripiprazole , Antipsychotics , Antinociceptive effect , Morphine , Mice