From the Pharmacy Department, South London and Maudsley NHS Foundation Trust, Denmark Hill, London, United Kingdom (Gee, Taylor); and the Institute of Pharmaceutical Sciences, King's College London, Franklin Wilkins Building, Stamford Street, London, United Kingdom (Gee, Taylor).
J Psychiatry Neurosci. 2021 Mar 11;46(2):E232-E237. doi: 10.1503/jpn.200208.
Monitoring of white cell counts during clozapine treatment leads to cessation of therapy if levels fall below predetermined values. Reductions in white cell counts, driven by lower levels of lymphocytes, have been observed with coronavirus disease 2019 (COVID-19). Neutropenia during COVID-19 has not been reported. We present data for 56 patients who were taking clozapine and had COVID-19.
We included patients who were taking clozapine at the time they tested positive for COVID-19. We compared absolute neutrophil counts, lymphocyte counts and white cell counts between baseline and the first week of infection, and baseline and the second week of infection.
We observed reductions in absolute neutrophil counts (p = 0.005), lymphocyte counts (p = 0.003) and white cell counts (p < 0.001) between baseline and the first 7 days of COVID-19. All cell counts had returned to baseline levels by days 8 to 14. Six patients experienced neutropenia (absolute neutrophil counts < 2.0 × 109/L) and of those, 4 underwent mandatory cessation of clozapine. For 3 patients, clozapine treatment had been established for more than 6 months with no previous neutropenia, neutrophil levels returned to baseline within 2 weeks and no further neutropenia was observed on restarting treatment.
This was a retrospective chart review; larger cohorts are required. Clozapine plasma levels were largely not measured by clinicians.
These data strongly suggest that mild neutropenia in the acute phase of COVID-19 in patients who are well established on clozapine is more likely to be a consequence of the virus than of clozapine treatment.
氯氮平治疗期间监测白细胞计数，如果水平低于预定值则停止治疗。新冠肺炎（COVID-19）导致白细胞计数下降，淋巴细胞水平降低。COVID-19 期间中性粒细胞减少尚未报道。我们提供了 56 名正在服用氯氮平且患有 COVID-19 的患者的数据。
我们纳入了在 COVID-19 检测呈阳性时正在服用氯氮平的患者。我们比较了基线时与感染后第一周和基线时与感染后第二周的绝对中性粒细胞计数、淋巴细胞计数和白细胞计数。
我们观察到在 COVID-19 感染的前 7 天，绝对中性粒细胞计数（p = 0.005）、淋巴细胞计数（p = 0.003）和白细胞计数（p < 0.001）均下降。所有细胞计数在第 8 至 14 天恢复到基线水平。6 名患者发生中性粒细胞减少症（绝对中性粒细胞计数 < 2.0 × 109/L），其中 4 名患者必须停止氯氮平治疗。对于 3 名患者，氯氮平治疗已建立 6 个月以上，且无既往中性粒细胞减少症，中性粒细胞水平在 2 周内恢复到基线，重新开始治疗后未再观察到中性粒细胞减少症。
这是一项回顾性图表审查；需要更大的队列。临床医生基本未测量氯氮平的血浆水平。
这些数据强烈表明，在已经确立氯氮平治疗的 COVID-19 急性期中，轻度中性粒细胞减少症更可能是病毒的结果，而不是氯氮平治疗的结果。
