Long-term treatment of chronic schizophrenia with risperidone: an open-label, multicenter study of 386 patients

An open-label, multicentre study was conducted to assess the long-term efficacy and safety of risperidone in patients with chronic schizophrenia. Three hundred and eighty-six patients at 70 centres in 11 countries received risperidone (2-16 mg/day) for up to 57 weeks; 247 patients were treated for at least 1 year. All but 48 patients had been treated with antipsychotic agents before entering the trial. The mean (+/- SD) daily risperidone dose at endpoint was 8.6 +/- 4.4 mg. The mean total Positive and Negative Syndrome Scale (PANSS) scores were reduced significantly from 76.7 at baseline to 67.4 at endpoint (p < 0.001). Even though no patients had acutely exacerbated symptoms at the start of the trial, mean scores on each of the PANSS positive, negative, and general psychopathology subscales were significantly reduced during the first month of open treatment, and these mean scores continued to improve over the course of the trial. At endpoint, 64% of patients were rated as improved on the Clinical Global Impression change scale. Extrapyramidal symptoms (scores on the Extrapyramidal Symptom Rating Scale) tended to decrease in severity or remained unchanged over the course of risperidone treatment; 27.7% of patients required antiparkinsonian medication during the study. The results demonstrate that risperidone's efficacy against the positive and negative symptoms of chronic schizophrenia can be maintained in long-term treatment with a low incidence of adverse experiences; moreover, the drug reduces preexisting extrapyramidal symptoms over time.