Severe neutropenia or agranulocytosis has been reported with many medications. With the exception of clozapine, this is a very rare side effect of antipsychotic medications. Accurate estimates of incidence are not possible, though this has been estimated to occur in about 1 in 5,000 patients. It has been reported with numerous antipsychotic medications, including amoxapine, aripiprazole, chlorpromazine, fluphenazine, haloperidol, olanzapine, risperidone, and thioridazine. However, there is no evidence that other medications do not also cause it.