Filgrastim is a man-made form of a protein that stimulates the growth of white blood cells in your body. White blood cells help your body fight against infection. Filgrastim is used to treat neutropenia, a lack of certain white blood cells caused by cancer, bone marrow transplant, receiving chemotherapy, or by other conditions. Filgrastim may also be used for purposes not listed in this medication guide.
Neupogen is most commonly used to to treat neutropenia, which is a condition where a person lacks white blood cells. Neupogen stimulates the blood system into creating more white blood cells. With more white blood cells, one has a better chance of fighting off infections.