Risperdal

Risperdal is the brand name for risperidone, an atypical antipsychotic used to treat certain psychiatric conditions. It is available in several forms, including oral tablets, orodispersible tablets, an oral solution, and a long-acting injectable formulation (Risperdal Consta) for schizophrenia and maintenance therapy in adults.

Risperidone acts as a dopamine D2 and serotonin 5-HT2A receptor antagonist, with an active metabolite, 9-hydroxyrisperidone, contributing to efficacy. It is approved for schizophrenia in adults and adolescents, manic or mixed episodes in bipolar disorder, and irritability associated with autism in children and adolescents.

The drug is primarily metabolized in the liver to 9-hydroxyrisperidone; both forms antagonize receptors and help control symptoms. Risperidone is excreted in urine and feces. Dosing depends on indication and patient factors; the long-acting injectable is typically given every two weeks.

Common adverse effects include drowsiness, dizziness, weight gain, increased appetite, and elevated prolactin that can cause galactorrhea or menstrual changes. Extrapyramidal symptoms and insomnia may occur, especially at higher doses. Serious but rare risks include neuroleptic malignant syndrome and tardive dyskinesia; metabolic effects and orthostatic hypotension can occur. There is an established increased risk of mortality in elderly patients with dementia-related psychosis when treated with antipsychotics, including risperidone.