Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder. It is taken either by mouth or by injection (subcutaneous or intramuscular). The injectable versions are long-acting and last for 2–4 weeks.Common side effects include movement problems, sleepiness, dizziness, trouble seeing, constipation, and increased weight. Serious side effects may include the potentially permanent movement disorder tardive dyskinesia, as well as neuroleptic malignant syndrome, an increased risk of suicide, and high blood sugar levels. In older people with psychosis as a result of dementia, it may increase the risk of death. It is unknown if it is safe for use in pregnancy. Its mechanism of action is not entirely clear, but is believed to be related to its action as a dopamine and serotonin antagonist.Study of risperidone began in the late 1980s and it was approved for sale in the United States in 1993. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 149th most commonly prescribed medication in the United States, with more than 4 million prescriptions. Medical uses
Risperidone is mainly used for the treatment of schizophrenia, bipolar disorder, and irritability associated with autism. Schizophrenia
Risperidone is effective in treating psychogenic polydipsia and the acute exacerbations of schizophrenia.Studies evaluating the utility of risperidone by mouth for maintenance therapy have reached varying conclusions.
The long-acting injectable form of risperidone may be advantageous over long acting first generation antipsychotics, as it is better tolerated (fewer extrapyramidal effects) and because long acting injectable formulations of first generation antipsychotics may increase the risk of depression. Autism
Compared to placebo, risperidone treatment reduces certain problematic behaviors in autistic children, including aggression toward others, self-injury, challenging behaviour, and rapid mood changes. The evidence for its efficacy appears to be greater than that for alternative pharmacological treatments. Weight gain is an important adverse effect. Some authors recommend limiting the use of risperidone and aripiprazole to those with the most challenging behavioral disturbances in order to minimize the risk of drug-induced adverse effects. Evidence for the efficacy of risperidone in autistic adolescents and young adults is less persuasive. Dementia
While antipsychotic medications such as risperidone have a slight benefit in people with dementia, they have been linked to higher incidence of death and stroke. Because of this increased risk of death, treatment of dementia-related psychosis with risperidone is not FDA approved and carries a black box warning. However many other jurisdictions regularly use it to control severe aggression and psychosis in those with dementia when other non-pharmacological interventions have failed and their pharmaceutical regulators have approved its use in this population.