Core Overview & Mechanism Risperidone is an atypical antipsychotic, classified as a serotonin-dopamine antagonist. Its primary efficacy arises from blocking dopamine D2 receptors, which targets the positive symptoms of schizophrenia, and blocking serotonin 5-HT2A receptors, which improves negative symptoms while lowering the risk of extrapyramidal symptoms (EPS) compared to conventional antipsychotics. It also antagonizes alpha-1 and H-1 histamine receptors, which can lead to orthostatic hypotension, sedation, and significant weight gain. The drug and its equally active major metabolite, 9-hydroxyrisperidone, are primarily metabolized by the CYP2D6 enzyme.

Boxed Warning Risperidone features a severe boxed warning for elderly patients with dementia-related psychosis, noting a significantly increased risk ...