Abstract
Risperidone is a novel atypical neuroleptic with a favorable profile of side effects due to its unique pharmacological activity: it exhibits both potent dopamine D2 and 5-HT2 receptor blocking activity, as well as high affinity for α1 and α2 adrenergic receptors and histamine H1 receptor. We found that risperidone has a potent antinociceptive effect in the tailflick assay with an ED50 of 26.4 mg/kg. This effect of risperidone was antagonized by naloxone (P < 0.05). This sensitivity to naloxone indicates that at least some of the analgesic effects of risperidone are mediated by an opioid mechanism of action. β-FNA (μ1 μ2-antagonist), naloxonazine (α1-antagonist) and norbinaltorphamine (nor-BNI; K1-analgesia) reversed risperidone antinociceptive effect (P < 0.05). Naltrindole (δ-antagonist) only partially reversed risperidone antinociceptive effect. We found that the sensitivity of risperidone antinociceptive effect to selective antagonists implies involvement of μ1-, μ2- and K1-opioid and to a lesser extent δ- opioid mechanisms. These results suggest a possible role for risperidone both in the management of pain and in the management of opiate withdrawal and detoxification.
Original language | English |
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Pages (from-to) | 25-28 |
Number of pages | 4 |
Journal | Neuroscience Letters |
Volume | 228 |
Issue number | 1 |
DOIs | |
State | Published - 30 May 1997 |
Keywords
- Antinociception
- Atypical neuroleptics
- Opioid receptor sub- types
- Risperidone