SIDE EFFECTS: Bone pain may occur. Taking a non-aspirin pain reliever such as acetaminophen may help with this pain. Ask your doctor or pharmacist for more details. Injection site reactions such as redness, swelling, itching, lumps, or bruising may also occur. If any of these effects persist or worsen, notify your doctor promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Get medical help right away if any of these rare but very serious side effects occur: breathing problems (e.g., trouble breathing, shortness of breath, fast breathing).

Rarely, possibly fatal damage to the spleen may occur. Get medical help right away if you experience the following side effects: stomach/abdominal pain and/or shoulder pain.

A very serious allergic reaction to this drug is unlikely, but get medical help right away if it occurs. Symptoms of a serious allergic reaction may include: rash, fast heartbeat, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Neulasta (pegfilgrastim) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before using pegfilgrastim, tell your doctor or pharmacist if you are allergic to it or to filgrastim; or to other medications made in a similar way (biotechnology-produced proteins using E. coli); or if you have any other allergies. This product may contain inactive ingredients (such as dry natural rubber/latex in the needle cover on the prefilled syringe), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: sickle cell disease, spleen problems.

If you are scheduled only for radiation therapy, pegfilgrastim may still help your body fight off infections. Discuss the risks and benefits with your doctor.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.