Clozapine: a comparison with other novel antipsychotics.

Clinical studies with clozapine have clearly demonstrated its superior efficacy over that of conventional antipsychotics in treatment-resistant schizophrenic patients. In comparative trials with these drugs, considerably more patients respond to treatment with clozapine than to conventional antipsychotic medication. Recently, new antipsychotics, such as olanzapine, quetiapine, risperidone, sertindole, and zotepine, have been introduced, but extensive data on their effects in treatment-resistant patients are not yet available. Published studies have drawn criticism in terms of inappropriate titration schedules, nonequivalent dosing between treatment groups, short treatment duration, and inadequate sample sizes. Further research will be needed to determine whether novel antipsychotics may substitute for clozapine in the future or whether clozapine will retain its unique role in the management of patients suffering from difficult-to-treat schizophrenic disorders.