Although
drug-induced
agranulocytosis is infrequent, it is of concern as the mortality rate ranges from 6 to 10%. Since the approval of
granulocyte colony-stimulating factor (
G-CSF) and
granulocyte-macrophage colony-stimulating factor (
GM-CSF), these drugs have been increasingly used in the management of
drug-induced
agranulocytosis. Unfortunately, most of the data regarding the use of these agents in patients with
drug-induced
agranulocytosis comes from case reports. In light of the low incidence of
drug-induced
agranulocytosis, the large variety of offending drugs with potentially different toxic mechanisms and the wide range of
neutropenia duration among patients with
agranulocytosis, randomised, double-blind studies are unlikely to be performed. Case reports provide promising results with a shortening in the duration of
agranulocytosis, a possible reduction in the duration of hospitalisation and the fatality rate in patients treated with haematopoietic
growth factors (HGF) compared with historical controls. A
therapeutic effect is also suggested by reports of reductions in the neutrophil count after HGF discontinuation following an initial increase. The results of recent case series are less positive, with only a moderate, but usually not significant, reduction in the duration of
neutropenia in patients treated with HGF, as compared with those receiving routine care. A Japanese study indicated that
G-CSF was effective in patients with mild-to-moderate
antithyroid drug-induced
neutropenia, whereas no clear benefit was apparent in those with severe
neutropenia. Several factors, for example, early recognition and improved management of individual cases with better supportive care, have contributed to a decrease in the overall mortality of
drug-induced
agranulocytosis. HGF are expected to further reduce mortality. Guidelines for the use of HGF in patients with
febrile neutropenia, as established by the American Society of Clinical Oncology, are probably valuable for the management of
drug-induced
agranulocytosis. In accordance with these recommendations, the use of HGF may be recommended in patients with severe
neutropenia and/or poor prognostic factors. Whether the absence of myeloid precursors or presence of promyelocytes or myelocytes in bone marrow examination represents optimal conditions for HGF treatment is still unknown. Most authors agree that treatment should be administered early in the course of the disease. An interesting approach, in which treatment decisions are based on the granulocyte count 4 hours after a single dose of
G-CSF in patients with anthithyroid
drug-associated
neutropenia should be more extensively evaluated.