How does this medication work? What will it do for me?

Filgrastim belongs to the family of medications known as granulocyte colony stimulating factors (G-CSF). It helps the bone marrow produce white blood cells which help the body fight infection.

Filgrastim is used to prevent infections caused by febrile neutropenia (a condition of low blood counts of a certain type of white blood cell known as neutrophils, accompanied by fever) for people who:

  • are receiving a type of chemotherapy that slows down white blood cell production,
  • are receiving bone marrow or stem cell transplants,
  • are taking certain medications to treat HIV infection,
  • have acute myeloid leukemia, or
  • have severe chronic neutropenia

Filgrastim may also be used to increase the numbers of certain types of blood cells.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Single use vials

Each mL of sterile, clear, colourless, preservative-free liquid for parenteral administration contains filgrastim 300 µg (3×107 units/mL) formulated in a 10 mM sodium acetate buffer at pH 4.0, containing 5% sorbitol, and 0.004% Tween 80. It is available in single use, preservative-free vials of 1 mL (filgrastim 300 µg) and 1.6 mL (filgrastim 480 µg).

Pre-filled syringes

Each mL of sterile, clear, colourless, preservative-free liquid for parenteral administration contains filgrastim 600 µg (3×107 units/mL) formulated in a 10 mM sodium acetate buffer at pH 4.0, containing 5% sorbitol, and 0.004% Tween 80. It is available in single use, preservative-free pre-filled syringes of 0.5 mL (filgrastim 300 µg) and 0.8 mL (filgrastim 480 µg). The needle cover on the pre-filled syringe contains dry natural rubber (latex).

How should I use this medication?

The recommended child and adult dose of filgrastim is based on body weight and varies depending on the circumstances of its use. Filgrastim is given by subcutaneous (under the skin) or intravenous (into a vein) injection. Your dose may be adjusted depending on your response to this medication and therapy is usually continued until neutrophil counts reach an acceptable level. For some conditions, filgrastim will be needed indefinitely.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Filgrastim is usually given under medical supervision. If you are giving filgrastim to yourself, your doctor or health care professional will instruct you on how to use filgrastim properly. It is important that this medication be used exactly as prescribed by your doctor.

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

If you are receiving this medication in a clinic or at your doctor's office and you miss an appointment to receive filgrastim, contact your doctor as soon as possible to reschedule your appointment.

This medication should be stored in the refrigerator, but do not allow it to freeze.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take filgrastim if you:

  • are allergic to filgrastim or to any of the ingredients of the medication
  • are allergic to products made using the E.coli bacteria
  • are allergic to latex (for the pre-filled syringe only)

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • mild-to-moderate bone pains or aches
  • reaction at the injection site (e.g., redness, swelling or itching)

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • bone pain or fractures
  • signs of bleeding (e.g., bloody nose, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
  • red or purple spots, patches, or lesions on the skin

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of acute respiratory distress syndrome (e.g., fever, shortness of breath, cough, or lung congestion)
  • signs of a ruptured spleen (e.g., abdominal pain on the upper left side or pain at the tip of the shoulder)
  • signs of a severe allergic reaction (e.g., hives, shortness of breath, wheezing, swelling of the face or throat, fast heart rate, dizziness)
  • signs of sickle cell crisis (e.g., severe pain in bones, chest, abdomen or joints)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


April 10, 2014

Health Canada has issued new restrictions concerning the use of Neupogen (filgrastim). To read the full Health Canada Advisory, visit Health Canada's web site at

Chronic use: When used for long periods of time, filgrastim may increase the risk of myelodysplasia (bone marrow disorders) and certain types of leukemia. It is not known if this increased risk is directly related to filgrastim or to the conditions filgrastim is being used to treat. If you are receiving long-term treatment with filgrastim, your doctor will monitor your blood regularly and check your bone marrow annually.

Cytotoxic chemotherapy: The safety of using filgrastim at the same time as cytotoxic chemotherapy (a type of chemotherapy that kills cells, especially cancer cells) has not been established. Filgrastim should not be used within 24 hours before or 24 hours after chemotherapy is administered.

Heart conditions: Heart-related conditions such as heart attacks and abnormal heart rhythms have been observed in rare cases with filgrastim. If you have had a heart condition before starting filgrastim, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Lung problems: Filgrastim may cause adult respiratory distress syndrome (ARDS), a serious lung condition, when people with neutropenia have a bacterial infection in the blood. If you experience difficulty breathing, fever or coughing blood while using filgrastim, contact your doctor immediately.

Osteoporosis: Long-term use of filgrastim may increase the risk of osteoporosis in some people. If you have chronic neutropenia or have osteoporosis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Your doctor may want to check your bone density regularly while you are receiving this medication.

Sickle cell disease: Filgrastim may cause sickle cell crisis when used by people who have sickle cell disease. You and your doctor should carefully consider the benefits and risks of using filgrastim in these circumstances if you have sickle cell disease.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known whether filgrastim passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of filgrastim have not been established for newborn babies.

What other drugs could interact with this medication?

There may be an interaction between filgrastim and any of the following:

  • bleomycin
  • lithium
  • other cytokine medications (e.g., growth factors)
  • topotecan

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.