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    Infection and Chemotherapy

    Strong chemotherapy can reduce your white blood cell count, weakening your immune system. A weakened immune system increases your risk of infection. Neulasta® is a prescription medication that can help protect against your risk of infection during strong chemotherapy. It does this by boosting the number of certain infection fighting white blood cells called neutrophils, which strengthens your immune system.

    Watch this video to learn more about how chemotherapy can weaken your immune system and what you can do to help protect against the risk of this potentially serious side effect of strong chemotherapy.

    Talk With Your Doctor Before Starting Strong Chemotherapy

    Your doctor may recommend that you take a prescription medication, like Neulasta®, that boosts the number of infection-fighting white blood cells called neutrophils. Neulasta® is a prescription medication given approximately 24 hours after you receive chemotherapy treatment. Neulasta® helps protect against the risk of infection and provides support through your chemotherapy cycle with just one injection. If you and your doctor decide to use the Neulasta® Onpro®, you may not have to return to the doctor the day after chemotherapy just for a Neulasta® injection. Neulasta® Onpro® is available at no extra cost beyond that of the Neulasta prefilled syringe.

    Learn About Neulasta® Onpro®

    WebMD does not endorse any specific product, service, or treatment.


    Neulasta® is a prescription medicine used to help reduce the chance of infection due to a low white blood cell count, in people with certain types of cancer (non-myeloid), who receive anti-cancer medicines (chemotherapy) that can cause fever and low blood cell count.

    Important Safety Information

    Who should not take Neulasta®?

    Do not take Neulasta® if you have had a serious allergic reaction to Neulasta® (pegfilgrastim) or NEUPOGEN® (filgrastim).

    What should I tell my health care provider before taking Neulasta®? Tell your healthcare provider if you:

    • Have sickle cell trait or sickle cell disease
    • Have had severe skin reactions to acrylic adhesives
    • Are allergic to latex
    • Have problems with your kidneys
    • Have any other medical problems
    • Are pregnant or plan to become pregnant. It is not known if Neulasta® may harm your unborn baby.
    • Are breastfeeding or plan to breastfeed. It is not known if Neulasta® passes into your breast milk.

    Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

    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. 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 healthcare provider or get emergency medical help right away if you get any of these symptoms of ARDS: fever, shortness of breath, trouble breathing, or a fast rate of breathing.
    • Serious Allergic Reactions. Get emergency medical help right away if you get any of these symptoms of a serious allergic reaction with Neulasta®: shortness of breath, wheezing, dizziness, swelling around the mouth or eyes, fast pulse, sweating, and hives.

    If you have an allergic reaction during the delivery of Neulasta®, remove the On-body Injector for Neulasta® by grabbing the edge of the adhesive pad and peeling off the On-body Injector. Get emergency medical help right away.

    • Sickle Cell Crises. Severe sickle cell crises, and sometimes death, can happen in people with sickle cell trait or disease who receive filgrastim, a medicine similar to Neulasta®.
    • Kidney injury (glomerulonephritis). Kidney injury has been seen in patients who received Neulasta®. You should notify your healthcare provider right away if you experience puffiness in your face or ankles, blood in your urine or brown colored urine or you notice you urinate less than usual.
    • Increased white blood cell count (leukocytosis). Your doctor will check your blood during treatment with Neulasta®.
    • Capillary Leak Syndrome. Neulasta® can cause fluid to leak from blood vessels into your body's tissues. This condition is called "Capillary Leak Syndrome" (CLS). CLS can quickly cause you to have symptoms that may become life-threatening. Get emergency medical help right away if you develop any of the following symptoms:
      • swelling or puffiness and are urinating less often
      • trouble breathing
      • swelling of your stomach-area (abdomen) and feeling of fullness
      • dizziness or feeling faint
      • a general feeling of tiredness

    The most common side effect of Neulasta® is pain in the bones and in your arms and legs.

    Tell your healthcare provider if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of Neulasta®. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088).

    For more information about Neulasta®, talk with your healthcare provider or pharmacist; go to, or call 1-844-696-3852 (1-844-MYNEULASTA).

    Please see Neulasta® Patient Information.

    Infection and Chemotherapy

    Strong chemotherapy can increase your risk of infection. Neulasta® can help.

    Learn More

    How Neulasta® Works

    Neulasta® helps protect against your risk of infection in a chemotherapy cycle with just one shot.

    Get the Details

    About Neulasta® Onpro®

    Consider the possibility of fewer doctor visits with Neulasta® Onpro®

    Learn More