Efficacy of Olanzapine: An Overview of Pivotal Clinical Trials

Olanzapine is a new "atypical" antipsychotic agent that belongs chemically to the thienobenzodiazepineclass. Its relatively greater binding affinity for 5-HT2 compared to D2 receptors makes it similarto the atypical agent clozapine, a serotonin/dopamine antagonist. Four double-blind pivotal studies,which compare olanzapine to placebo and/or haloperidol, are presented. The results suggest thatolanzapine is as effective as haloperidol for positive symptoms and more effective than haloperidolfor the treatment of the negative symptoms of schizophrenia.