Risk of neutropenia among clozapine users and non-users: results from 5,847 patients

• Autor(a) principal: Goldani,André Akira Sueno
• Data de Publicação: 2022
• Outros Autores: Rabelo-da-Ponte,Francisco Diego, Feiten,Jacson Gabriel, Lobato,Maria Ines R., Belmonte-de-Abreu,Paulo S., Gama,Clarissa S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Psychiatry (São Paulo. 1999. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-44462022000100021
• topic: Clozapine; neutropenia; hematological monitoring; hemogram; absolute neutrophil count

Objective: Clozapine is underprescribed due to neutropenia risk. Blood tests every 3 months in those on continuous treatment for > 1 year who have never had an absolute neutrophil count (ANC) < 2,000/µL has been proposed as a monitoring strategy; however, there are no South American data to support this recommendation. This study sought to investigate whether clozapine use and other variables could explain the occurrence of ANC < 1,000/µL in patients with severe mental disorders. Methods: A total of 5,847 subjects were included, 1,038 on clozapine. We performed a Cox regression considering the outcome as ANC < 1,000/µL at any time point. Predictors were sex, age, ethnicity, clozapine use, ANC > 2,000/µL during the first year of blood monitoring, and presence of a severe medical condition. Results: In the Cox regression model, ethnicity (white) (hazard ratio [HR] 0.53; 95%CI 0.29-0.99, p < 0.05) and ANC > 2,000/µL (HR 0.04; 95%CI 0.01-0.10, p < 0.001) were protective factors, while presence of a severe medical condition (HR 69.35; 95%CI 37.45-128.44, p < 0.001) was a risk factor for ANC < 1,000/µL. Other variables were not significant, including clozapine use (HR 1.33; 95%CI 0.74-2.39, p > 0.05). Conclusions: These findings suggest that clozapine does not increase the risk of neutropenia in subjects with ANC > 2,000/µL during the first year of use and in the absence of a severe medical condition. These results could help guide clinical and public-health decisions regarding clozapine blood monitoring guidelines.