Care During Chemotherapy and Beyond



Trade name:  Neupogen®
Other names:  G-CSF, granulocyte - colony stimulating factor uses generic names in all descriptions of drugs. G-CSF is the trade name for filgrastim. Neopogen is another name for filgrastim. In some cases, health care professionals may use the trade name G-CSF or other names neupogen when referring to the generic drug name filgrastim.

Drug type:  Filgrastim is a biologic response modifier.  It is classified as a colony stimulating factor.  (For more detail, see "How this drug works" section below).

What Filgrastim Is Used For:

  • Filgrastim is used to stimulate the production of granulocytes (a type of white blood cell) in patients undergoing therapy that will cause low white blood cell counts.  This medication is used to prevent infection and neutropenic (low white blood cells) fevers caused by chemotherapy.
  • Filgrastim is a support medication.  It does not treat cancer.

Note:  If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How Filgrastim Is Given:

  • Filgrastim may be given by subcutaneous (the layer between the skin and muscle) injection or infused into a vein (intravenous, IV).
  • Filgrastim is generally given on a daily basis.  The number of days you receive filgrastim will be prescribed by your doctor.
  • Filgrastim should be refrigerated.  Remove from refrigerator 30 minutes before injection.  Do not shake the medication.  
  • The amount of filgrastim that you will receive depends on many factors, including your height and weight, your general health or other health problems, and the type of cancer or condition being treated.  Your doctor will determine your dose and schedule.

Side Effects:

Important things to remember about the side effects of filgrastim:

  • Most people do not experience all of the side effects listed.
  • Side effects are often predictable in terms of their onset and duration.
  • Side effects are almost always reversible and will go away after treatment is complete.
  • There are many options to help minimize or prevent side effects.
  • There is no relationship between the presence or severity of side effects and the effectiveness of the medication.
  • Filgrastim is a support medication.  The following list includes side effects attributed to filgrastim.  Other side effects experienced were attributed to the chemotherapy and/or the disease.

The following side effects are common (occurring in greater than 30%) for patients taking filgrastim:

Note:  There are no common side effects of filgrastim.

These side effects are less common side effects (occurring in about 10-29%) of patients receiving filgrastim:

  • Pain (bone pain)
  • Blood test abnormalities (temporary elevation in lactate dehydrogenase, and alkaline phosphatase).  These will return to normal once treatment is discontinued.
  • Tenderness at the site of injection

Not all side effects are listed above. Some that are rare (occurring in less than 10% of patients) are not listed here.  However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

  • Fever of 100.4° F (38° C) or higher, chills (possible signs of infection)
  • Shortness of breath
  • Rapid heart beat
  • Bleeding that does not stop after a few minutes
  • Any new rashes on your skin

The following symptoms require medical attention, but are not an emergency. Contact your health care provider within 24 hours of noticing any of the following:

  • Bone pain that does not go away despite taking recommended pain reliever

Always inform your health care provider if you experience any unusual symptoms.


  • Before starting filgrastim treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.).   Do not take aspirin, products containing aspirin unless your doctor specifically permits this.
  • The manufacturer recommends that the first dose of filgrastim be given no sooner than 24 hours after chemotherapy.  Your doctor will discontinue therapy with filgrastim when your white blood cell count has reached acceptable levels.
  • Filgrastim may be inadvisable if you have had a hypersensitivity reaction to filgrastim or E. coli-derived proteins.
  • Do not receive any kind of immunization or vaccination without your doctor's approval while taking filgrastim.
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment.  Pregnancy category C (use in pregnancy only when benefit to the mother outweighs risk to the fetus).
  • For both men and women: Do not conceive a child (get pregnant) while taking filgrastim. Barrier methods of contraception, such as condoms, are recommended. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
  • Do not breast feed while taking this medication.
  • Filgrastim should be used with caution in people taking lithium.

Self-Care Tips:

  • If you are performing your own subcutaneous self-injections, remove the syringe from the refrigerator 30 minutes prior to injection.  This will reduce local stinging at the injection site.
  • You may experience bone or joint pain as a result of this medication. Ask your healthcare provider if you may take a mild pain medicine to relieve this.  Acetominophen (Tylenol®) may help.
  • Apply a warm compress if you have any pain, redness or swelling at the injection site, and notify your doctor.
  • You may be at risk of infection so try to avoid crowds or people with colds, and report fever or any other signs of infection immediately to your health care provider.
  • Wash your hands often.
  • Avoid contact sports or activities that could cause injury.
  • This medication causes little nausea. But if you should experience nausea, take anti-nausea medications as prescribed by your doctor, and eat small, frequent meals. Sucking on lozenges, and chewing gum may also help.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely.  You should discuss this with your doctor.
  • Get plenty of rest. 
  • Maintain good nutrition.
  • If you experience symptoms or side effects, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing:

You will be checked regularly by your health care professional while you are taking filgrastim to monitor side effects and check your response to therapy.  Periodic blood work to monitor your complete blood count (CBC) as well as the function of other organs (such as your kidneys and liver) will also be ordered by your doctor.   

How This Drug Works:

Colony-Stimulating Factors:
In the body's bone marrow (the soft, sponge-like material found inside bones) blood cells are produced.  There are three major types of blood cells; white blood cells, which fight infection; red blood cells, which carry oxygen to and remove waste products from organs and tissues; and platelets, which enable the blood to clot.  Cancer treatments such as chemotherapy and radiation therapy can effect these cells which put a person at risk for developing infections, anemia and bleeding problems.  Colony-stimulating factors are substances that stimulate the production of blood cells and promote their ability to function.   They do not directly affect tumors but through their role in stimulating blood cells they can be helpful as support of the persons immune system during cancer treatment.

Filgrastim is a growth factor that stimulates the production, maturation and activation of neutrophils.  Filgrastim also stimulates the release of neutrophils (a type of white blood cell) from the bone marrow.  In patients receiving chemotherapy, filgrastim can accelerate the recovery of neutrophils, reducing the neutropenic phase (the time in which people are susceptible to infections).

Note:  We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit