Clozapine: a novel antipsychotic.

Clozapine is the first truly new antipsychotic drug introduced in the last 40 years. Compared to traditional neuroleptic agents, clozapine appears to have a stronger effect on most schizophrenic symptoms. Thus, it seems to be more effective than other agents in severely ill, treatment-resistant patients. Clozapine rarely causes extrapyramidal symptoms such as pseudoparkinsonism or akathisia. To date, no confirmed cases of tardive dyskinesia have been attributed to the drug. Despite these advantages, the usefulness of clozapine is limited by its potentially life-threatening side effects, which include agranulocytosis and respiratory depression.