Skip to main content

Zarxio Dosage

Generic name: FILGRASTIM 300ug in 0.5mL
Dosage form: injection, solution
Drug class: Colony stimulating factors

Medically reviewed by Drugs.com. Last updated on Aug 15, 2024.

Dosage in Patients with Cancer Receiving Myelosuppressive Chemotherapy or Induction and/or Consolidation Chemotherapy for AML

The recommended starting dosage of ZARXIO is 5 mcg/kg/day‚ administered as a single daily injection by subcutaneous injection‚ by short intravenous infusion (15 to 30 minutes)‚ or by continuous intravenous infusion. Obtain a complete blood count (CBC) and platelet count before instituting ZARXIO therapy and monitor twice weekly during therapy. Consider dose escalation in increments of 5 mcg/kg for each chemotherapy cycle‚ according to the duration and severity of the absolute neutrophil count (ANC) nadir. Recommend stopping ZARXIO if the ANC increases beyond 10‚000/mm3.

Administer ZARXIO at least 24 hours after cytotoxic chemotherapy. Do not administer ZARXIO within the 24-hour period prior to chemotherapy. A transient increase in neutrophil count is typically seen 1 to 2 days after initiation of ZARXIO therapy. Therefore, to ensure a sustained therapeutic response‚ administer ZARXIO daily for up to 2 weeks or until the ANC has reached 10‚000/mm3 following the expected chemotherapy-induced neutrophil nadir. The duration of ZARXIO therapy needed to attenuate chemotherapy-induced neutropenia may be dependent on the myelosuppressive potential of the chemotherapy regimen employed.

Dosage in Patients with Cancer Undergoing Bone Marrow Transplantation

The recommended dosage of ZARXIO following bone marrow transplantation (BMT) is 10 mcg/kg/day given as an intravenous infusion no longer than 24 hours. Administer the first dose of ZARXIO at least 24 hours after cytotoxic chemotherapy and at least 24 hours after bone marrow infusion. Monitor CBCs and platelet counts frequently following marrow transplantation.

During the period of neutrophil recovery‚ titrate the daily dosage of ZARXIO against the neutrophil response (see Table 1).

Table 1. Recommended Dosage Adjustments During Neutrophil Recovery in Patients with Cancer Following BMT
Absolute Neutrophil Count ZARXIO Dosage Adjustment
*
If ANC decreases to less than 1,000/mm3 at any time during the 5 mcg/kg/day administration‚ increase ZARXIO to 10 mcg/kg/day‚ and then follow the above steps.

When ANC greater than 1,000/mm3 for 3 consecutive days

Reduce to 5 mcg/kg/day*

Then, if ANC remains greater than 1,000/mm3 for 3 more consecutive days

Discontinue ZARXIO

Then, if ANC decreases to less than 1,000/mm3

Resume at 5 mcg/kg/day

Dosage in Patients Undergoing Autologous Peripheral Blood Progenitor Cell Collection and Therapy

The recommended dosage of ZARXIO for the mobilization of autologous peripheral blood progenitor cells (PBPC) is 10 mcg/kg/day given by subcutaneous injection. Administer ZARXIO for at least 4 days before the first leukapheresis procedure and continue until the last leukapheresis. Although the optimal duration of ZARXIO administration and leukapheresis schedule have not been established‚ administration of filgrastim for 6 to 7 days with leukaphereses on days 5‚ 6‚ and 7 was found to be safe and effective. Monitor neutrophil counts after 4 days of ZARXIO‚ and discontinue ZARXIO if the white blood cell (WBC) count rises to greater than 100‚000/mm3.

Dosage in Patients with Severe Chronic Neutropenia

Prior to starting ZARXIO in patients with suspected chronic neutropenia, confirm the diagnosis of severe chronic neutropenia (SCN) by evaluating serial CBCs with differential and platelet counts‚ and evaluating bone marrow morphology and karyotype. The use of ZARXIO prior to confirmation of a correct diagnosis of SCN may impair diagnostic efforts and may thus impair or delay evaluation and treatment of an underlying condition‚ other than SCN‚ causing the neutropenia.

The recommended starting dosage in patients with Congenital Neutropenia is 6 mcg/kg as a twice daily subcutaneous injection and the recommended starting dosage in patients with Idiopathic or Cyclic Neutropenia is 5 mcg/kg as a single daily subcutaneous injection.

Dosage Adjustments in Patients with Severe Chronic Neutropenia

Chronic daily administration is required to maintain clinical benefit. Individualize the dosage based on the patient’s clinical course as well as ANC. In the SCN postmarketing surveillance study, the reported median daily doses of filgrastim were: 6 mcg/kg (congenital neutropenia), 2.1 mcg/kg (cyclic neutropenia), and 1.2 mcg/kg (idiopathic neutropenia). In rare instances, patients with congenital neutropenia have required doses of filgrastim greater than or equal to 100 mcg/kg/day.

Monitor CBCs for Dosage Adjustments

During the initial 4 weeks of ZARXIO therapy and during the 2 weeks following any dosage adjustment‚ monitor CBCs with differential and platelet counts. Once a patient is clinically stable‚ monitor CBCs with differential and platelet counts monthly during the first year of treatment. Thereafter, if the patient is clinically stable, less frequent routine monitoring is recommended.

Important Administration Instructions

ZARXIO (for subcutaneous use or intravenous use) is supplied in single-dose vials and in single-dose prefilled syringes.

Patients who will self-administer and caregivers who will administer to the patient may benefit from training by a healthcare professional. Training should aim to demonstrate to those patients and caregivers how to measure the dose of ZARXIO, and the focus should be on ensuring that a patient or caregiver can successfully perform all of the steps in the Instructions for Use for the vial or prefilled syringe with BD UltraSafe Passive® Needle Guard. If a patient or caregiver is not able to demonstrate that they can measure the dose and administer the product successfully, you should consider whether the patient is an appropriate candidate for self-administration of ZARXIO prefilled syringe or whether the patient would benefit from the ZARXIO vial presentation. If a patient or caregiver experiences difficulty measuring the required dose, especially if it is other than the entire content of the ZARXIO prefilled syringe, use of the ZARXIO vial may be considered.

Administration Instructions for Subcutaneous Injection

Inject ZARXIO subcutaneously in the outer area of upper arms, abdomen, thighs, or upper outer areas of the buttock. If patients or caregivers are to administer ZARXIO, instruct them in appropriate injection technique and ask them to follow the subcutaneous injection procedures in the Instructions for Use for prefilled syringe with BD UltraSafe Passive ® Needle Guard or for the vial.

If the patient or caregiver misses a dose of ZARXIO, instruct them to contact their healthcare provider.

Instructions for the Prefilled Syringe

ZARXIO prefilled syringe with BD UltraSafe Passive® Needle Guard is not designed to allow for direct administration of doses of less than 0.3 mL (180 mcg). The spring-mechanism of the needle guard apparatus affixed to the prefilled syringe interferes with the visibility of the graduation markings on the syringe barrel corresponding to 0.1 mL and 0.2 mL. The visibility of these markings is necessary to accurately measure doses of ZARXIO less than 0.3 mL (180 mcg) for direct administration to patients. Thus, the direct administration to patients requiring doses of less than 0.3 mL (180 mcg) is not recommended due to the potential for dosing errors. If less than 0.3 mL is needed the ZARXIO single-dose vial should be used.

Persons with latex allergies should not administer the ZARXIO prefilled syringe, because the needle cap contains natural rubber latex (derived from latex). For latex sensitive individuals the ZARXIO vial should be considered as the vial stopper is not made with natural rubber latex.

Prior to use‚ remove the prefilled syringe from the refrigerator and allow ZARXIO to reach room temperature [between 20°C to 25°C (68°F to 77°F)] for a minimum of 30 minutes. If not used immediately, the prefilled syringe may be stored at room temperature for up to 8 days. Discard any prefilled syringe left at room temperature for greater than 8 days. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit (the solution is clear and colorless to slightly yellowish). Do not administer ZARXIO if particulates or discoloration are observed.

Discard unused portion of ZARXIO in prefilled syringes. Do not save unused drug for later administration.

Instructions for the Single-dose vial

Prior to use‚ remove the vial from the refrigerator and allow ZARXIO to reach room temperature for a minimum of 30 minutes. If not used immediately, the vial may be stored at room temperature for up to 8 days. Discard any vial left at room temperature for greater than 8 days. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit (the solution is clear and colorless to slightly yellowish). Do not administer ZARXIO if particulates or discoloration are observed.

Discard the unused portion of ZARXIO in single-dose vial and do not re-enter the vial. Do not save unused drug for later administration.

Administration Instructions for Dilution

If required for intravenous administration ZARXIO may be diluted in 5% Dextrose Injection, USP to concentrations between 5 mcg/mL and 15 mcg/mL. ZARXIO diluted to concentrations from 5 mcg/mL to 15 mcg/mL should be protected from adsorption to plastic materials by the addition of Albumin (Human) to a final concentration of 2 mg/mL. When diluted in 5% Dextrose Injection, USP, or 5% Dextrose plus Albumin (Human)‚ ZARXIO is compatible with glass, polyvinylchloride, polyolefin, and polypropylene.

Do not dilute with Sodium Chloride Injection at any time, because the product may precipitate.

Diluted ZARXIO solution from ZARXIO prefilled syringe can be stored at room temperature [between 20℃ to 25℃ (68℉ to 77℉)] for up to 24 hours. This 24‑hour time period includes the time during room temperature storage of the infusion solution and the duration of the infusion.

Diluted ZARXIO solution from ZARXIO vial can be stored refrigerated [2°C to 8°C (36°F to 46°F)] for up to 24 hours or at room temperature [between 20℃ to 25℃ (68℉ to 77℉)] for up to 4 hours, including the time during room temperature storage of the infusion solution and the duration of the infusion.

Frequently asked questions

Further information

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