The present invention concerns methods comprising co-administration of pegfilgrastim and romiplostim for treatment of diseases and conditions characterized by low neutrophil levels (neutropenia) and/or low platelet levels (thrombocytopenia). The present invention concerns an enhanced effect on neutrophil levels and on platelet levels resulting from co-administration of pegfilgrastim and romiplostim. The present invention further concerns a method of treating a patient who has been exposed to radiation, which comprises administering romiplostim at a dose of about 1 to about 10 g/kg. The invention further concerns such methods wherein a single dose of romiplostim is administered to the patient and wherein romiplostim is administered about 24 hours or less after the radiation exposure. The invention further concerns treatment with romiplostim and pegfilgrastim for radiation exposure. Such methods relate to treatment of acute radiation syndrome and treatment to counteract the effects of radiation therapy and other sources of radiation exposure.
