Filgrastim, sold under the brand name Neupogen, is often given by injection to patients suffering from neutropenia, or a low neutrophil count. Neupogen stimulates the production of white blood cells, which in turn boosts the body's production of neutrophils, About.com explains. Neutrophils are key components in fighting infections.
Medical treatment of neutropenia depends in part on the cause of the low neutrophil count, states WebMD. Other medical treatments for low neutrophil count may include antibiotics to fight bacterial infection, treatment with granulocyte colony-stimulating factor to stimulate the bone marrow's production of neutrophils, and stem cell transplants for severe neutropenia caused by problems with the bone marrow.