How it is administered

Filgrastim is available as a clear, colorless, preservative-free liquid for injection. It comes in single-dose vials or prefilled syringes for subcutaneous (under the skin) or intravenous (into the vein) use. The medication is typically given as a daily injection, either by a healthcare provider or, after proper training, by the patient or caregiver at home. The dose and duration depend on your weight, blood counts, and the reason for use. Always follow your healthcare provider's instructions for administration.

How it works

Filgrastim is a man-made form of a naturally occurring protein called granulocyte colony-stimulating factor (G-CSF). This protein helps your body make more neutrophils, a type of white blood cell that fights infection. Filgrastim works by binding to specific receptors on cells in the bone marrow, stimulating them to grow, mature, and be released into the bloodstream.

In patients with blood cancers like Adult T-cell Leukemia/Lymphoma, chemotherapy can significantly lower neutrophil counts, increasing the risk of infection. Filgrastim helps reduce the duration and severity of neutropenia (low neutrophil counts), thereby lowering the risk of infections and related complications. The effect is usually seen within a few days, and neutrophil counts return to normal after stopping the medication.

Who Should take it

Filgrastim is used in adults and children with non-myeloid blood cancers (such as Adult T-cell Leukemia/Lymphoma) who are receiving chemotherapy that causes significant neutropenia (low white blood cell counts). It is also used in patients undergoing bone marrow transplantation, those collecting stem cells for transplant, and people with severe chronic neutropenia from other causes.

For blood cancer patients, filgrastim helps reduce the risk and duration of infections during treatment. Your doctor may recommend filgrastim if your chemotherapy regimen is expected to cause a significant drop in neutrophil counts or if you have a history of infections related to low white blood cells.

Who should not take it

You should not take filgrastim if you have had a serious allergic reaction to filgrastim, pegfilgrastim, or any other G-CSF products. Signs of a serious allergic reaction include rash, swelling, trouble breathing, or low blood pressure. It is also not recommended for people with certain types of blood cancers (like chronic myeloid leukemia or myelodysplastic syndromes) unless specifically directed by your doctor, as it may stimulate these cancer cells.

Patients with sickle cell disease should use filgrastim with caution, as it can cause severe sickle cell crises. If you have a history of kidney disease, glomerulonephritis, or certain other medical conditions, your doctor will decide if filgrastim is safe for you.

Commonly used with

Filgrastim is commonly used alongside chemotherapy regimens for blood cancers, including Adult T-cell Leukemia/Lymphoma. It may also be used with other supportive care medications such as antibiotics (to treat or prevent infections), anti-nausea medications, and pain relievers.

In stem cell transplantation, filgrastim is used with procedures like leukapheresis to collect stem cells from the blood.

Commonly tested with

Filgrastim has been tested in combination with various chemotherapy drugs used for blood cancers, such as cyclophosphamide, doxorubicin, etoposide, and others. It is also studied with bone marrow transplantation protocols and stem cell mobilization regimens.

In clinical trials, filgrastim is often compared to placebo or other growth factors to evaluate its effectiveness in reducing infection rates, hospitalizations, and improving recovery of white blood cell counts after chemotherapy or transplantation.