Treatment of the symptoms of schizophrenia: a combined analysis of double-blind studies comparing risperidone with haloperidol and other antipsychotic agents

Combined data on efficacy were available from 12 double-blind short-term (m aximum 8 weeks) trials comparing risperidone and other antipsychotics in pa tients with chronic schizophrenia. Patients received risperidone (n = 1056) or other antipsychotics (n = 703). Haloperidol (n = 473) was the most freq uently prescribed other antipsychotic. Efficacy assessments include the Pos itive and Negative Syndrome Scale (PANSS) total, subscale (positive symptom s, negative symptoms and general psychopathology), cluster (cognitive and a ffective symptoms) and item (anxiety and hostility) scores. At endpoint, th e mean decrease from baseline in PANSS total scores was significantly great er for patients receiving risperidone (-20.9) than other antipsychotics (-1 6.2; P < 0.001), or the subset receiving haloperidol (-14.3; P < 0.001). Ri speridone-treated patients showed a significantly greater decrease in the p ositive (P < 0.01), negative (P < 0.05) and general psychopathology (P < 0. 001) scores than patients receiving other antipsychotics or haloperidol. Sc ores for cognition, affective symptoms, anxiety and hostility each improved significantly (P < 0.05) more for patients receiving risperidone than thos e receiving other antipsychotics or haloperidol. Efficacy data on patients with an acute exacerbation were available from seven trials (risperidone n = 372, other antipsychotics n = 285, including haloperidol n = 120). At end point, the mean decrease from baseline in PANSS total scores was significan tly greater for patients receiving risperidone (-24.7) than other antipsych otics (-19.8, P < 0.01) including haloperidol (-19.8, P < 0.05). Risperidon e-treated patients also showed a greater decrease in positive symptom score s (-7.8) than those receiving other antipsychotics (-6.3; P < 0.01) or halo peridol (-7.1). A <greater than or equal to> 20% reduction in PANSS total s core with risperidone, haloperidol and other antipsychotics was achieved by 65.9%, 54.3% and 54.9%, respectively; a greater than or equal to 30% PANSS reduction by 54.0%, 46.6% and 46.5% of patients, respectively; and a great er than or equal to 40% reduction by 43.8%, 33.7% and 34.4% of patients, re spectively. These findings are consistent with earlier findings that show r isperidone is more efficacious than haloperidol for reducing the symptoms o f schizophrenia. Int Clin Psychopharmacol 16:265-274 (C) 2001 Lippincott Wi lliams & Wilkins.