Schulte Peter F J
Mental Health Services North-Holland North, Department De Dijk, Kennemerstraatweg 464, 1851 NG Heiloo, Netherlands.
Ann Pharmacother. 2006 Apr;40(4):683-8. doi: 10.1345/aph.1G396. Epub 2006 Mar 7.
To provide information for physicians and patients on which to base a decision as to whether to stop mandatory blood testing.
Articles on drug-induced blood dyscrasias were identified by searches of MEDLINE (1966-September 2005) and review of their bibliographies. Novartis was asked to provide additional data on clozapine, leukopenia, agranulocytosis, and suicidality.
Data on the chance of clozapine-induced leukopenia and agranulocytosis were combined with data about possible fatality and compared with the risks associated with other medications and with life in general.
The chance of clozapine-induced leukopenia or agranulocytosis decreases exponentially over time. In the US, the chance in the second 6 months of treatment is 0.70/1000 patient-years and, after the first year, 0.39/1000 patient-years. The case fatality rate of clozapine-induced agranulocytosis is estimated as 4.2-16%, depending on whether a granulocyte colony-stimulating factor is used. Nevertheless, treatment with clozapine reduces overall mortality, probably because it reduces suicidality.
After at least 6 months' treatment with clozapine, the mortality involved in stopping white blood cell monitoring is about the same as the mortality associated with other medications, such as mianserin or phenylbutazone, and with life in general (traffic or occupational accident). If the patient has been well informed and wishes to stop the monitoring, it is a medically justifiable option to do so and is preferable to stopping treatment with clozapine since this drug reduces overall mortality.
为医生和患者提供信息，以便他们就是否停止强制性血液检测做出决策。
通过检索MEDLINE（1966年至2005年9月）并查阅其参考文献，确定了关于药物性血液系统疾病的文章。已要求诺华公司提供有关氯氮平、白细胞减少症、粒细胞缺乏症和自杀倾向的额外数据。
将氯氮平诱发白细胞减少症和粒细胞缺乏症的几率数据与可能的致死率数据相结合，并与其他药物及一般生活中的风险进行比较。
氯氮平诱发白细胞减少症或粒细胞缺乏症的几率随时间呈指数下降。在美国，治疗的第二个6个月中发生率为0.70/1000患者年，第一年之后为0.39/1000患者年。根据是否使用粒细胞集落刺激因子，氯氮平诱发粒细胞缺乏症的病死率估计为4.2% - 16%。然而，氯氮平治疗可降低总体死亡率，可能是因为它降低了自杀倾向。
在使用氯氮平治疗至少6个月后，停止白细胞监测所涉及的死亡率与其他药物（如米安色林或保泰松）及一般生活（交通或职业事故）相关的死亡率大致相同。如果患者已充分了解情况并希望停止监测，那么这样做在医学上是合理的选择，并且比停止使用氯氮平治疗更可取，因为这种药物可降低总体死亡率。
