Risperidone, a benzisoxazole derivative, acts as a dopamine type 2 (D
2) and serotonin type 2 (5-HT
2) receptors antagonist. In addition, risperidone has affinity for α
1- and α
2-adrenergic, and H
1 histaminergic receptors. While, risperidone has low to moderate affinity for the serotonin 5-HT
1C, 5-HT
1D and 5-HT
1A receptors, week affinity for the dopamine D
1 and haloperidol-sensitive sigma binding site, and no affinity for cholinergic muscarinic or β
1 and β
2 adrenergic receptors. Its major active metabolite is paliperidone (9-hydroxyrisperidone) [
P1897]. Risperidone is used as a long acting antipsychotic agent with relatively few side effects. (The product is for research purpose only.)