What receptors are chiefly involved in mediating the antipsychotic effects of risperidone?

The antipsychotic effects of risperidone are chiefly mediated through the blockade of dopamine D2 receptors. Risperidone is an atypical antipsychotic that acts primarily as an antagonist of these D2 receptors in the mesolimbic dopamine pathway. This action helps alleviate positive symptoms of schizophrenia, such as hallucinations and delusions.

In addition to its effects on dopamine receptors, risperidone also antagonizes serotonin 5-HT2 receptors, which contributes to its therapeutic profile and may help with both positive and negative symptoms of schizophrenia. However, the most significant receptor in terms of its primary action regarding antipsychotic effects is the dopamine D2 receptor.

The other receptors listed, such as alpha-adrenoceptors and histamine receptors, do play roles in the pharmaceutical effects of risperidone, particularly in terms of side effects, but they are not primarily responsible for its antipsychotic efficacy. Understanding these mechanisms helps clarify the action of risperidone and its place within the treatment landscape for psychotic disorders.