An open-label, multicenter evaluation of the long-term safety and efficacy of risperidone in adolescents with schizophrenia

BACKGROUND: Data on the long-term efficacy, safety, and tolerability of risperidone in adolescents with schizophrenia are limited. The objective of this study was to evaluate the efficacy and safety of maintenance risperidone treatment in adolescents with schizophrenia. METHODS: This open-label study of adolescents aged 13 to 17 years with schizophrenia was a single extension study of two short-term double-blind risperidone studies and also enrolled subjects directly in open-label risperidone treatment. The risperidone dose was flexible and ranged from 2 to 6 mg/day. Most subjects enrolled for 6 months; a subset enrolled for 12 months. Assessment tools included the Positive and Negative Syndrome Scale total and factor scores, Clinical Global Impressions, Children’s Global Assessment Scale, adverse event (AE) monitoring, vital signs, laboratory testing, and extrapyramidal symptom rating scales. RESULTS: A total of 390 subjects were enrolled; 48 subjects had received placebo in a previous double-blind study; 292 subjects had received risperidone as part of their participation in one of two previous controlled studies; and 50 subjects were enrolled directly for this study. A total of 279 subjects enrolled for 6 months of treatment, and 111 subjects enrolled for 12 months of treatment. Overall, 264 (67.7%) subjects completed this study: 209 of the 279 subjects (75%) in the 6-month group and 55 of the 111 subjects (50%) in the 12-month group. The median mode dose was 3.8 mg/day. At 6 months, all three groups experienced improvement from open-label baseline in symptoms of schizophrenia as well as general assessments of global functioning. Improvements were generally maintained for the duration of treatment. The most common AEs (≥10% of subjects) were somnolence, headache, weight increase, hypertonia, insomnia, tremor, and psychosis. Potentially prolactin-related AEs (PPAEs) were reported by 36 (9%) subjects. The AE profile in this study was qualitatively similar to those of other studies in adult subjects with schizophrenia and in other psychiatric studies of risperidone in pediatric populations. CONCLUSIONS: Risperidone maintenance treatment in adolescents over 6 to 12 months was well tolerated, consistent with related studies in this clinical population, and associated with continued efficacy. CLINICAL TRIALS: ClinicalTrials.gov registration number: NCT00246285 http://clinicaltrials.gov/ct2/show/NCT00246285?term=NCT00246285&rank=1