Reviewed on 5/2/2023

Generic Name: Filgrastim

Brand Name: G-CSF, Neupogen, tbo-filgrastim, Granix, Zarxio, filgrastim-sndz, Nivestym, filgrastim-aafi

Drug Class: Hematopoietic Growth Factors

What Is Filgrastim and How Does It Work?

Filgrastim is a man-made form of granulocyte colony-stimulating factor (G-CSF) that promotes the growth of neutrophils to boost the body’s immunity to fight against infection.

  • Filgrastim is available under the following different brand names: G-CSF, Neupogen, tbo-filgrastim, Granix, Zarxio, filgrastim-sndz, Nivestym, filgrastim-aafi

What Are Dosages of Filgrastim?

Adult and pediatric dosage

Injectable solution, single-dose vials

Neupogen, Granix, Nivestym

  • 300mcg/mL
  • 480mcg/1.6mL

Injectable solution, prefilled syringe for SC

Neupogen, Granix, Nivestym, Zarxio

  • 300mcg/0.5mL
  • 480mcg/0.8mL

Biosimilars to Neupogen

Zarxio (filgrastim-sndz)

Granix (tbo-filgrastim)

Nivestym (filgrastim-aafi)

Myelosuppressive Chemotherapy Treatment

Adult and pediatric dosage

  • Neupogen, Zarxio, Nivestym: 5 mcg/kg/day SC or IV infusion (short 15-30 min or continuous); may increase by 5 mcg/kg increments according to duration and severity of ANC
  • Granix: 5 mcg/kg/day SC

Induction or Consolidation Chemotherapy

Adult dosage

  • 5 mcg/kg SC/IV once daily initially; may increase by 5 mcg/kg for each chemotherapy cycle according to duration and severity of ANC

Bone Marrow Transplantation

Adult dosage

  • Following BMT: 10 mcg/kg/day IV infusion over 4-24 hours (do not exceed 24-hours infusion)

Pediatric dosage

  • 10 mcg/kg/day IV infusion

Peripheral Blood Progenitor Cell Collection

Adult and pediatric dosage

  • 10 mcg/kg/day SC 

Severe Chronic Neutropenia

Adult dosage

Pediatric dosage

  • Congenital neutropenia: 6 mcg/kg/day SC divided twice daily
  • Idiopathic or cyclic neutropenia: 5 mcg/kg SC once daily

Acute Radiation Syndrome

Adult dosage

  • 10 mcg/kg SC as a single daily injection for patients exposed to myelosuppressive doses of radiation

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Are Side Effects Associated with Using Filgrastim?

Common side effects of Filgrastim include:

  • fever, 
  • pain, 
  • rash, 
  • cough, 
  • shortness of breath
  • nose bleed, 
  • headache
  • decreased red blood cells,
  • diarrhea,
  • reduced sensation, and 
  • hair loss

Serious side effects of Filgrastim include:

  • allergic reactions: rash over the whole body, shortness of breath, wheezing, dizziness, swelling around the mouth or eyes, fast heart rate, sweating,
  • spleen rupture,
  • acute respiratory distress syndrome,
  • sickle cell crises,
  • kidney injury (glomerulonephritis): swelling of the face or ankles, blood in the urine or dark-colored urine, decreased frequency of urination,
  • capillary leak syndrome: swelling or puffiness, decreased urination, trouble breathing, swelling of the abdomen, feeling of fullness, dizziness, a general feeling of tiredness,
  • myelodysplastic syndrome and acute myeloid leukemia: tiredness, fever, and easy bruising or bleeding,
  • thrombocytopenia,
  • leucocytosis, 
  • hemoptysis
  • cutaneous vasculitis: purple spots or redness of the skin, and
  • aortitis: fever, abdominal pain, feeling tired, and back pain.

Rare side effects of Filgrastim include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Filgrastim?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Filgrastim has no noted severe interactions with any other drugs.
  • Filgrastim has no noted serious interactions with any other drugs.
  • Filgrastim has no noted moderate interactions with any other drugs.
  • Filgrastim has no noted minor interactions with any other drugs. 

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Filgrastim?


  • History of serious allergic reactions to filgrastim or pegfilgrastim products

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Filgrastim?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Filgrastim?”


  • Allergic reactions reported (angioneurotic edema, dermatitis-allergic, hypersensitivity, rash, pruritic rash, and urticaria); allergic reactions can recur within days after discontinuation of initial antiallergic treatment; permanently discontinue therapy in patients with serious allergic reactions
  • Associated with rare cases of potentially fatal splenic rupture; evaluate if patient experiences left upper abdominal and/or shoulder tip pain
  • Rare cases of ARDS reported; evaluate patients who develop fever and lung infiltrates or respiratory distress for ARDS; discontinue therapy in patients with ARDS
  • Monitor for thrombocytopenia
  • Severe and sometimes fatal sickle cell crises can occur in patients with sickle cell disorders; discontinue therapy if sickle cell crisis occurs
  • Glomerulonephritis reported; if suspected, evaluate for a cause; if causality likely, consider dose-reduction or interruption
  • The increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone imaging changes; this should be considered when interpreting bone imaging results
  • WBC counts above100‚000/mm³ were observed in ~2% of patients receiving filgrastim at dosages more than 5 mcg/kg/day
  • Off-label use for PBPC mobilization has resulted in alveolar hemorrhage, resulting in pulmonary infiltrates and hemoptysis
  • Cutaneous vasculitis has been reported; hold therapy in patients with cutaneous vasculitis; therapy may be started at a reduced dose when the symptoms resolve and the ANC has decreased
  • Capillary leak syndrome (CLS) can occur in patients receiving filgrastim products and is characterized by hypotension, hypoalbuminemia, edema, and hemoconcentration; patients who develop symptoms of CLS should be closely monitored and receive standard symptomatic treatment, which may include a need for intensive care
  • In patients with cancer receiving the drug as an adjunct to myelosuppressive chemotherapy‚ to avoid the potential risks of excessive leucocytosis, ‚ recommended that therapy be discontinued if the ANC surpasses 10‚000/mm³ after the chemotherapy-induced ANC nadir has occurred; monitor CBC counts at least twice weekly during therapy; dosages that increase the ANC beyond 10‚000/mm³ may not result in any additional clinical benefit
  • During the period of administration of therapy for PBPC mobilization in patients with cancer, discontinue therapy if leukocyte count rises  above10‚000/mm³
  • Simultaneous use with chemotherapy and radiation therapy is not recommended
  • The increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone imaging changes; consider when interpreting bone imaging results
  • The increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone imaging changes; this should be considered when interpreting bone imaging results
  • Aortitis
    • Aortitis has been reported; may occur as early as the first week after the start of therapy
    • Manifestations may include generalized signs and symptoms such as fever, abdominal pain, malaise, back pain, and increased inflammatory markers (eg, C-reactive protein and WBC)
    • Consider aortitis in patients who develop these signs and symptoms without known etiology
    • Discontinue if aortitis is suspected
  • Severe chronic neutropenia
  • Confirm if patients have severe chronic neutropenia (SCN)
  • Myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML) have been reported to occur in the natural history of congenital neutropenia without cytokine therapy
  • MDS and AML reported in patients with breast and lung cancer receiving chemotherapy and/or radiotherapy; monitor patients for signs and symptoms of MDS/AML in these settings
  • Effect of filgrastim on the development of abnormal cytogenetics and the effect of continued administration in patients with abnormal cytogenetics or MDS are unknown
  • If a patient with SCN develops abnormal cytogenetics or myelodysplasia‚ the risks and benefits should be carefully considered before continuing treatment
  • Drug interaction overview
    • Drugs that may potentiate the release of neutrophils‚ such as lithium‚ should be used with caution
    • Safety and efficacy of concomitantly using filgrastim with cytotoxic chemotherapy or radiation therapy have not been established; because of the potential sensitivity of rapidly dividing myeloid cells to cytotoxic chemotherapy‚ do not use in the period 24 hours before through 24 hours after the administration of cytotoxic chemotherapy

Pregnancy and Lactation

  • Available data from published studies, including several observational studies of pregnancy outcomes in women exposed to filgrastim products and those who were unexposed, have not established an association with use during pregnancy and major birth defects, miscarriage, or adverse maternal or fetal outcomes
  • Reports in the scientific literature have described the transplacental passage of drugs in pregnant women when administered less than or equal to 30 hours before preterm delivery (less than or equal to 30 weeks gestation)
  • Lactation
    • There is published literature documenting the transfer of filgrastim into human milk; there are a few case reports describing the use of filgrastim in breastfeeding mothers with no adverse effects noted in the infants; there are no data on effects of filgrastim on milk production; other filgrastim products are secreted poorly into breast milk, and filgrastim products are not absorbed orally by neonates; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on the breastfed child from the drug or underlying maternal condition
Medscape. Nivestym.

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