About Low White Blood Cell Counts

Chemotherapy can weaken your natural defenses

Chemotherapy (also known as chemo) works by killing fast-growing cancer cells. Unfortunately, chemotherapy drugs can't always tell the difference between cancer cells and fast-growing healthy cells, including red and white blood cells. As a result, one of the potential side effects of many types of chemotherapy drugs can be a low white blood cell count.1 Chemo that causes this side effect is described as myelosuppressive (my-eh-low-suh-PRESS-iv), because it suppresses your production of white blood cells. A low number of a specific type of white blood cells called neutrophils—also known as neutropenia (new-tro-pee-nee-uh)—can put some patients at risk for infections and may interrupt chemo treatment.1 In fact, complications associated with a low white blood cell count are the most common causes of dose reductions or delays in chemotherapy.2 A sufficient white blood cell count may enable your doctors to administer chemotherapy according to their treatment schedule.

A low white blood cell count can interrupt chemotherapy

The fewer number of white blood cells you have and the longer you remain without enough, the greater your risk for developing an infection, some of which may be life threatening, potentially resulting in hospitalization for febrile neutropenia (fever and neutropenia) and administration of IV antibiotic therapy.1,2

Therefore, your doctor may need to delay chemo treatment or reduce your chemotherapy dose until your white blood cell count increases and the possibility of infection is reduced.3

Healthy vs. Neutropenic Immune System1

Healthy vs. Neutropenic Immune System
Normal:
White blood cells are a key part of your natural defenses, your immune system. At normal levels, white blood cells help protect your body against infection.		 Neutropenic:
Chemotherapy can reduce your white blood cell count. A low white blood cell count means your immune system isn't as strong as it could be and you are at increased risk of infection and interruptions in your chemotherapy.

For more information about low white blood cell counts, please visit the following resources:

Indication

Neulasta® (pegfilgrastim) is a prescription medication used to reduce the risk of infection (initially marked by fever) in patients with some tumors receiving strong chemotherapy that decreases the number of infection-fighting white blood cells.

Important Safety Information

Who should not take Neulasta®?
Do not take Neulasta® if you have had an allergic reaction to Neulasta® (pegfilgrastim) or to NEUPOGEN® (Filgrastim).

What should I tell my health care provider before taking Neulasta®?
If you have a sickle cell disorder, make sure your doctor knows about it before using Neulasta®.

What are possible serious side effects of Neulasta®?
  • Spleen Rupture. Your spleen may become enlarged and can rupture while taking Neulasta®. A ruptured spleen can cause death. The spleen is located in the upper left section of your stomach area. Call your doctor right away if you have pain in the left upper stomach area or left shoulder tip area. This pain could mean your spleen is enlarged or ruptured.
  • A serious lung problem called acute respiratory distress syndrome (ARDS). Call your doctor or seek emergency care right away if you have shortness of breath, trouble breathing, or a fast rate of breathing.
  • Serious Allergic Reactions. Neulasta® can cause serious allergic reactions. These reactions can cause shortness of breath, wheezing, dizziness, swelling around the mouth or eyes, fast pulse, sweating, and hives. If you start to have any of these symptoms, call your doctor or seek emergency care right away. If you have an allergic reaction during the injection of Neulasta®, stop the injection. Call your doctor right away.
  • Sickle Cell Crises. You may have a serious sickle cell crisis if you have a sickle cell disorder and take Neulasta®. Serious and sometimes fatal sickle cell crises can occur in patients with sickle cell disorders receiving Filgrastim, a medicine similar to Neulasta®. Call your doctor right away if you have symptoms of sickle cell crisis such as pain or difficulty breathing.

What are the most common side effects of Neulasta®?
The most common side effect you may experience is aching in the bones and muscles. If this happens, it can usually be relieved with a nonaspirin pain reliever, such as acetaminophen.

What important information do I need to know about receiving Neulasta®?
  • Occasionally pain and redness may occur at the injection site. If there is a lump, swelling, or bruising at the injection site that does not go away, talk to the doctor.
  • Neulasta® should only be injected on the day the doctor has determined and should not be injected until approximately 24 hours after receiving chemotherapy.
  • The needle cover on the single-use prefilled syringe contains dry natural rubber (latex), which should not be handled by persons sensitive to this substance.

If you have any questions about this information, be sure to discuss them with your doctor. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

Next: Who is Most at Risk? >>

References:
  1. Wujcik D. Infection. In: Groenwald SL, Goodman M, Frogge MH, Yarbro CH, eds. Cancer Symptom Management. Boston, Mass: Jones & Bartlett Publishers; 1996:289-304.
  2. Bodey, G., et al. Quantitative Relationships Between Circulating Leukocytes and Infection in Patients With Acute Leukemia. Ann Int Med. 1966; 64: 328-340.
  3. Link BK, Budd GT, Scott S, et al. Delivering adjuvant chemotherapy to women with early-stage breast carcinoma. Cancer. 2001;92:1354-1367.