risperidone

Risperidone is an atypical antipsychotic medication used to treat several mental health conditions. It primarily acts as an antagonist of dopamine D2 receptors and serotonin 5-HT2A receptors in the brain, which is believed to contribute to its antipsychotic and mood-stabilizing effects. The drug also has activity at other receptors, including alpha-adrenergic and histaminergic receptors, which can influence blood pressure, sedation, and other side effects. After administration, risperidone is metabolized in the liver to 9-hydroxyrisperidone (paliperidone), an active metabolite; together, the parent drug and metabolite provide therapeutic effect.

Approved indications include schizophrenia in adults and adolescents, bipolar disorder (manic or mixed episodes), and irritability associated with autism in children and adolescents. Dosing and formulation vary: oral tablets or an orally disintegrating tablet, oral solution; and a long-acting injectable form (Risperdal Consta) administered every two weeks for schizophrenia and related conditions in appropriate patients.

Common adverse effects include extrapyramidal symptoms (such as stiffness, tremor, restlessness), and elevations in prolactin that can cause galactorrhea, amenorrhea, or sexual dysfunction. Other potential effects include weight gain, glucose intolerance, dyslipidemia, sedation, and orthostatic hypotension. The risk of death with use in elderly people with dementia-related psychosis is higher compared with placebo. Risperidone may cause pregnancy risk C and can be excreted in breast milk; use during breastfeeding is generally advised only if benefits outweigh risks.

Clinicians monitor metabolic parameters, weight, glucose, and lipids, as well as signs of EPS and prolactin-related effects. Drug interactions include CYP2D6 inhibitors or inducers, which can alter risperidone levels. Dose adjustments may be needed in liver impairment or when used with other central nervous system depressants.