大约有25%的精神分裂症病人对氟哌啶醇和氯丙嗪等传统的抗精神病药无效,而非典型抗精神病药氯氮平则可对其中30%的病人有效。由于氯氮平的服用者中有2%～3%的人可能产生中性白细胞减少和粒细胞缺乏症,故在治疗中应作血液学监测。氯氮平引起粒细胞降低的作用机理目前尚无定论。 Approximately 25% of schizophrenic patients are ineffective with traditional antipsychotics such as haloperidol and chlorpromazine, while clozapine, a typical antipsychotic drug, is effective in 30% of patients. As clozapine users in 2% to 3% of people may produce neutropenia and agranulocytosis, it should be used in the treatment of hematology monitoring. The mechanism by which clozapine causes neutropenia is not known yet.