Zarxio

Generic name: filgrastim-sndz [ fil-GRAS-tim ]
Drug class: Colony stimulating factors

Medically reviewed by Philip Thornton, DipPharm. Last updated on Apr 2, 2025.

What is Zarxio?

Zarxio (filgrastim-sndz) 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.

Zarxio is used to decrease the chance of infection in people who have non myeloid cancer (cancer that does not involve the bone marrow) and are receiving chemotherapy medications that may decrease the number of neutrophils (a type of blood cell needed to fight infection).

Zarxio is also used to help increase the number of white blood cells, and decrease the length of time with fever in people with acute myeloid leukemia (AML; a type of cancer of the white blood cells) who are receiving treatment with chemotherapy medications.

Zarxio is also used in people who are undergoing bone marrow transplants and in people who have severe chronic neutropenia (condition in which there are a low number of neutrophils in the blood).

Zarxio is also used to prepare the blood for leukapheresis (a treatment in which certain blood cells are removed from the body.

Zarxio increases the chance of survival in people exposed to harmful amounts of radiation with Acute Radiation Syndrome (ARS). The effectiveness of filgrastim for this use was only studied in animals because it could not be studied in people.

Filgrastim-sndz belongs to a class of medications called colony-stimulating factors. It works by stimulating the growth of neutrophils, a type of white blood cell important in the body’s fight against infection.

Warnings

Zarxio 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.

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

Before taking this medicine

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

Using Zarxio 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.

To make sure Zarxio is safe for you, tell your doctor if you have ever had:

• sickle cell anemia (a hemoglobin blood cell disorder);

• latex allergy;

• radiation treatment; or

• kidney disease.

It is not known if filgrastim-sndz 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.

How should I use Zarxio?

Use Zarxio exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Zarxio is injected under the skin (subcutaneously). A healthcare provider may teach you or your caregiver how to properly use this medication at home.

Doses are based on weight. Your dose may change if you gain or lose weight.

Your healthcare provider will show you where to inject Zarxio. Do not inject into the same place two times in a row.

Do not inject into areas where the skin is tender, bruised, red, or hard. Avoid injecting into skin that has scars or stretch marks.

Do not change your dose or stop using a medicine without your doctor's advice.

Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using only the medicine your doctor prescribes. Do not switch brand forms without your doctor's advice.

Ask your doctor or pharmacist if you don't understand how to use an injection.

Prepare an injection only when you are ready to give it. Call your pharmacist if the medicine looks cloudy, has changed colors or has particles in it.

Do not reuse a needle or syringe. Place them in a puncture-proof "sharps" container and dispose of it following state or local laws. Keep out of the reach of children and pets.

If you are receiving Zarxio because you are also receiving chemotherapy, the last dose of Zarxio should be injected at least 24 hours before your next dose of chemotherapy.

Your doctor will do blood tests before and during treatment with Zarxio to check your blood cell counts and to check for any side effects.

Filgrastim-sndz can affect the results of certain medical tests. Tell any doctor who treats you that you are using Zarxio.

Store Zarxio prefilled syringes in the original container in a refrigerator, away from light. Do not freeze and do not shake.

Do not warm the medicine with hot water, sunlight, or a microwave.

Take the medicine out of the refrigerator and let it reach room temperature for 30 minutes before using. Do not leave Zarxio out for longer than 24 hours.

Throw away a prefilled syringe or vial (bottle) after one use, even if there is still medicine left inside.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Zarxio?

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

Zarxio side effects

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

Zarxio 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.

Zarxio 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.

Zarxio may cause serious side effects. 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 Zarxio 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.

Related/similar drugs

What other drugs will affect Zarxio?

Do not use Zarxio within 24 hours before or after you receive chemotherapy, or within 24 hours after a bone marrow transplant.

Other drugs may interact with filgrastim-sndz, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Ingredients

Active ingredient: filgrastim-sndz
Inactive ingredient: glutamic acid, polysorbate 80, sorbitol, sodium hydroxide, water for injection USP.

Manufacturer

Sandoz Inc., Princeton, NJ 08540, USA, at: GP Grenzach Produktions GmbH, Grenzach-Wyhlen, Germany.

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Zarxio Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There are 2 for Zarxio.

Neupogen biosimilar products

Biosimilar products can only be dispensed in place of the reference product if the healthcare provider specifically prescribes the biosimilar product by name.

Pharmacy laws for biosimilar prescribing may vary by state

Popular FAQ

More FAQ

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Zarxio only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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