White blood cells, known as leukocytes, protect the body from foreign particles such as viruses, bacteria, fungi and parasites. Because white blood cells live only a day or two, the immature stem cells in the bone marrow continually produce new white blood cells to replace the damaged and dying cells. A decrease in white blood cells, caused by medications or disease, affects the immune system and leaves the body vulnerable to fight potentially life-threatening infections. Two medications approved by the U.S. Food and Drug Administration increase the production of white blood cells.
White Blood Cells
White blood cells consist of five different types of cells; neutrophils, eosinphils, basophils, monocytes and lymphocytes. Each performs a specialized function in the immune system. The Merck Manual says that neutrophils make up 45 percent to 75 percent of the total white blood cells and therefore affect the total number of white cells the most. They, alsong with eosinophils and basophils, all belong to the class of cells known as granulocytes. Granulocytes, named for the characteristic granules in their cytoplasm, protect the body from bacterial infections. Drugs that promote the formation of granulocytes help to protect the body from serious infections.
Deficiency
Undergoing chemotherapy treatment, the use of toxic drugs to kill cancer cells, is the main cause of a deficiency in white blood cells. Chemotherapy drugs target rapidly dividing cells, which include not only cancer cells but also certain types of healthy cells, such as blood cells. The decrease in white blood cells makes cancer patients susceptible to infections that can interfere with their recovery. Taking drugs to increase the production of white cells boosts their immune system.
Granulocyte Colony Stimulating Factor
Doctors classify drugs that increase the production of white blood cells as granulocyte colony stimulating factors. Granulocyte colony stimulating factors stimulate the stem cells in the bone marrow to produce neutrophils. These medications also help the neutrophils mature and activate into functioning white cells in the blood, according to Chemocare.com.
Available Formulations
Chemotherapy patients can benefit from taking one of the two available formulations of a granulocyte colony stimulating factor medication. The Food and Drug Administration approved the medication filgrastim in 1991 to treat patients with a compromised immune system due to chemotherapy or radiation treatments, according to the Centers for Disease Control and Prevention. A similar medication, pegfilgrastim, contains the same active ingredients with the addition of polyethylene glycol, which helps the medication stay in the body longer, therefore prolonging the effects.
Side Effects
Although these medications increase the number of white blood cells to help the body fight infections, they can also cause unwanted side effects. Side effects of filgrastim and pegfilgrastim include fever, skin rash, diarrhea, bone pain and weakness. Patients with a sensitivity to E. coli produced proteins can experience an allergic reaction and should therefore avoid these medications.
