Low-dose continuous subcutaneous infusion of granulocyte colony-stimulating factor for chemotherapy-induced neutropenia in acute myelogenous leukemia and its pharmacokinetics.

Granulocyte colony-stimulating factor (G-CSF) shortens the duration of chemotherapy-induced granulocytopenia in acute leukemia. G-CSF is administered by 30-min intravenous infusion at a dose of 200 micrograms/m2/day or 5 micrograms/kg/day in most studies. In this study, the efficacy of a reduced dose (33 micrograms/m2/day) of continuous subcutaneous infusion of G-CSF was compared with the effects achieved by 30-min intravenous infusion of the standard dose (200 micrograms/m2/day) in neutropenia after identical chemotherapy in seven patients with acute myelogenous leukemia who were in remission. The duration of granulocytopenia (< 0.5 x 10(9)/l), thrombocytopenia (< 50 x 10(9)/l); G-CSF administration and fever (> 38 degrees C) were 10.1 +/- 5.0 days, 16.5 +/- 9.3 days, 16.6 +/- 7.4 days and 3.1 +/- 5.4 days for 33 micrograms/m2/day continuous subcutaneous infusion, and 10.7 +/- 6.8 days, 16.7 +/- 9.9 days, 16.1 +/- 7.6 days and 2.0 +/- 2.5 days for 30-min intravenous infusion of the standard dose of G-CSF. In each parameter studied, there was no statistical difference between the two methods of G-CSF administration by paired t-test. The costs for G-CSF could be substantially reduced. In most patients, plasma G-CSF concentration rose to the highest level of 1.8-3.7 ng/ml 48-72 h after starting 33 micrograms/m2/day continuous subcutaneous infusion, and gradually decreased as the peripheral granulocyte count recovered, suggesting binding of G-CSF molecules to the specific receptors on the cells of granulocytic lineage.