Refractory schizophrenia and atypical antipsychotics.

Treatment resistant or refractory schizophrenia is a difficult to define condition of largely unknown prevalence. For 10 years, clozapine has been the standard treatment in this condition and is recognized unequivocally as being effective. However, clozapine is sometimes poorly tolerated and has the potential for severe toxicity. Partly as a result of this, other atypicals have recently been evaluated as treatments for refractory schizophrenia. In order to evaluate the evidence base relating to the drug treatment of refractory schizophrenia, we developed a refractoriness rating based on previous work. Using this rating, we assessed all trials of atypicals in schizophrenia unresponsive to at least one drug. Overall, clozapine was consistently shown to be effective in refractory schizophrenia, even when stringently defined. Data relating to olanzapine and risperidone are equivocal at best, and there is some evidence to suggest that they are less effective than clozapine. There is essentially no cogent evidence to support the use of any other atypical in refractory schizophrenia. Clozapine remains the drug of choice in this condition.