Effect of granulocyte colony-stimulating factor on neutropenia due to chemotherapy for non-Hodgkin's lymphoma. The authors administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) to 16 patients with advanced non-Hodgkin's lymphoma treated with combination chemotherapy. Groups of three to five patients were treated with 50, 100, 200, and 400 micrograms/m2 per day of rhG-CSF by intravenous infusion for 14 days, beginning 3 days after chemotherapy. There was a strong linear relationship between the dose and the area under the curve over this dose range. The rhG-CSF was rapidly cleared from serum, with a mean half-life of 5.97 hours for the second phase (t1/2). In patients treated with a dose of more than 100 micrograms/m2 per day, the duration of neutropenia (P less than 0.01) and the duration of fever (P less than 0.05) were significantly decreased. The rhG-CSF was well tolerated and the only clinical observation that appeared relating to rhG-CSF administration was slight bone pain. This study strongly suggests that an optimum dose of rhG-CSF in patients after chemotherapy is 100 to 200 micrograms/m2. Our study shows that rhG-CSF is a clinically useful drug for patients treated with myelosuppressive chemotherapy. 