The Food and Drug Administration (FDA) recently approved risperidone (Risperdal) for the short-term treatment of manic or mixed episodes of bipolar I disorder in 10-to-17-year-olds and for the treatment of schizophrenia in 13-to-17-year-olds. It is the first atypical antipsychotic to be approved for either disorder in those age groups. (Lithium, which is not an antipsychotic, had been the only drug approved for the treatment of bipolar disorder in adolescents.) Risperidone was first approved in 1993 for treating schizophrenia in adults. Approval was later extended to treating acute manic or mixed episodes of bipolar I disorder in adults and irritability associated with autistic disorder in children ages five to 16, but because pediatric patients were excluded from the original clinical trials, clinicians had to prescribe it "off label" for children. In an effort to ensure better and safer care for children, Congress passed the Best Pharmaceuticals for Children Act in January 2002, under which the FDA can request that a drug manufacturer sponsor clinical trials of pediatric populations to establish a drug's efficacy and safety in those patients. In return, the manufacturer is granted six-month exclusivity to market the product for use in pediatric populations.

The requested clinical trials of risperidone's use in children demonstrated that its pharmacokinetics are comparable in various age groups (after correcting for body weight) and that it effectively and safely treats both bipolar I disorder and schizophrenia. Although the dose of risperidone in children and adolescents does not need to be adjusted according to body weight, doses must be lower than those used in adults (4 to 8 mg daily for schizophrenia in adults, 3 mg daily in adolescents; 1 to 6 mg daily for bipolar mania in adults, 2.5 mg daily in children and adolescents). Risperidone's most common adverse effects are drowsiness, fatigue, increased appetite, anxiety, nausea, dizziness, dry mouth, tremor, and rash. Nurses should be familiar with the recent revisions to the labeling of risperidone so that they can guide parents and patients.