Clinical improvement in 336 stable chronically psychotic patients changed from oral to long-acting risperidone: a 12-month open trial.

Modern atypical antipsychotics have advantages over older neuroleptics. We hypothesize that their utility may be further enhanced by sustained drug delivery without daily oral self-dosing. This report examines the effects of a year of treatment with long-acting risperidone for chronically psychotic patients previously stabilized with oral risperidone. This open trial of long-acting risperidone involved 336 patients diagnosed with DSM-IV schizophrenia or schizoaffective disorder judged clinically stable on a consistent daily oral dose of risperidone for > or =4 wk. Based on oral doses, subjects were assigned clinically to bi-weekly intramuscular injections of 25-75 mg of long-acting risperidone for up to 50 wk. Clinical assessments at regular intervals included the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions (CGI) scale, adverse event reports, and the Extrapyramidal Symptom Rating Scale (ESRS). PANSS total scores improved overall from a moderate baseline score of 64.5+/-17.7 to 58.8+/-19.9 at end-point (p<0.001), by> or =20% in 50% of patients, with greatest improvement in negative symptoms. Prevalence of favourable CGI - Severity ratings increased by 2.4-fold (p<0.0001). Ratings of extrapyramidal symptoms also improved [e.g. physician-rated parkinsonism scores decreased by 20% (p<0.0001)]. Tissue reactions and other adverse effects of repeated intramuscular injections were rare and mild. Psychotic patients considered stable but symptomatic with oral risperidone treatment showed further improvements in symptom ratings and extrapyramidal dysfunction during a year of bi-weekly injections of long-acting risperidone.