Filgrastim is used to treat neutropenia (lack of certain white blood cells) in patients receiving certain cancer medications, undergoing a bone marrow transplant, or caused by other conditions.

Neupogen, Zarxio, and Nivestym can be used in a procedure called leukapheresis, where white blood cells needed for a stem cell transplant are removed from the body.

Neupogen is also used in patients who have been exposed to a certain amount of radiation.

Filgrastim may also be used for purposes not listed in this medication guide.

You should not use this medicine if you are allergic to filgrastim or other granulocyte colony stimulating factor such as pegfilgrastim, tbo-filgrastim, sargramostim, or eflapegrastim.

Using filgrastim may increase your risk of developing myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) if you have certain medical conditions. Ask your doctor about this risk.

Tell your doctor if you have or have ever had:

• sickle cell anemia (a hemoglobin blood cell disorder);
• latex allergy;
• radiation treatment; or
• kidney disease.

It is not known if filgrastim will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Ask a doctor if it is safe to breastfeed while using this medicine.

Use Neupogen Singleject (Injectable) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives, sweating, rash, dizziness, fast heart rate, wheezing, difficult breathing, swelling of your face, lips, tongue, or throat.

Filgrastim can cause a serious lung problem called acute respiratory distress syndrome (ARDS) and a rare but serious side effect called capillary leak syndrome. Call your doctor or seek emergency medical attention right away if you have fever with shortness of breath or rapid breathing, stuffy or runny nose followed by tiredness, thirst, decreased urination, and sudden swelling or weight gain.

Filgrastim can cause your spleen to become enlarged, and it could rupture (tear). Call your doctor right away if you have left-sided upper stomach pain or left shoulder pain.

Some side effects may occur during the injection. Tell your medical caregiver if you feel dizzy, nauseated, light-headed, itchy, sweaty, or have a headache, chest tightness, back pain, trouble breathing, or swelling in your face.

Call your doctor at once if you have:

• easy bruising, unusual bleeding, purple or red spots of your skin or under your skin;
• fever, tiredness, stomach pain, back pain;
• signs of sickle cell anemia crisis--pain or difficulty breathing;
• inflammation of your blood vessels--numbness or tingling, skin rash, fever, headache, body aches, night sweats, weight loss, feeling or weak or tired; or
• kidney problems--swelling, urinating less, feeling tired or short of breath.

Common side effects may include:

• fever, pain, cough, trouble breathing;
• nosebleeds;
• anemia (low red blood cells);
• bone pain;
• diarrhea;
• headache;
• numbness; or
• rash, hair loss.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.