This may also lead to drowsiness and weight gain.Voltage-gated sodium channels: Because it accumulates in synaptic vesicles, Risperidone inhibits voltage-gated sodium channels at clinically used concentrations. Pharmacokinetics
Risperidone undergoes hepatic metabolism and renal excretion. Lower doses are recommended for patients with severe liver and kidney disease. The active metabolite of risperidone, paliperidone, is also used as an antipsychotic. Society and culture
Legal status
Risperidone was approved by the United States Food and Drug Administration (FDA) in 1993 for the treatment of schizophrenia. In 2003, the FDA approved risperidone for the short-term treatment of the mixed and manic states associated with bipolar disorder. In 2006, the FDA approved risperidone for the treatment of irritability in autistic children and adolescents. The FDAs decision was based in part on a study of autistic people with severe and enduring problems of violent meltdowns, aggression, and self-injury; risperidone is not recommended for autistic people with mild aggression and explosive behavior without an enduring pattern. On 22 August 2007, risperidone was approved as the only drug agent available for treatment of schizophrenia in youths, ages 13–17; it was also approved that same day for treatment of bipolar disorder in youths and children, ages 10–17, joining lithium. On 16 December 2021, the Committee for Medicinal Products for Human Use (CHMP)  of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Okedi, intended for the  treatment of schizophrenia in adults for whom tolerability and effectiveness has been established with oral risperidone.
The applicant for this medicinal product is Laboratorios Farmacéuticos Rovi, S.A. Risperidone was approved for medical use in the European Union in February 2022. Availability
Janssens patent on risperidone expired on 29 December 2003, opening the market for cheaper generic versions from other companies, and Janssens exclusive marketing rights expired on 29 June 2004 (the result of a pediatric extension). It is available under many brand names worldwide.Risperidone is available as a tablet, an oral solution, and an ampule, which is a depot injection. Lawsuits
On 11 April 2012, Johnson & Johnson (J&J) and its subsidiary Janssen Pharmaceuticals Inc. were fined $1.2 billion by Judge Timothy Davis Fox of the Sixth Division of the Sixth Judicial Circuit of the U.S. state of Arkansas. The jury found the companies had downplayed multiple risks associated with risperidone.