FILGRASTIM 30MIU

Indications

• Neutropenia associated with chemotherapy
• Reduction in duration of neutropenia after myeloablative therapy followed by bone marrow transplantation
• Mobilisation of peripheral blood progenitor cells for autologous infusion
• Severe congenital neutropenia
• Persistent neutropenia in HIV infection

Dosage

Adults: For adults, filgrastim is typically administered as follows: 10 micrograms/kg daily, starting at least 24 hours after cytotoxic chemotherapy or within 24 hours of bone marrow infusion

Mechanism of action

Filgrastim acts by binding to the granulocyte-colony stimulating factor receptor (G-CSFR) on hematopoietic progenitor cells in the bone marrow. This binding stimulates the proliferation, differentiation, and activation of neutrophil precursors, leading to increased production and release of neutrophils into the bloodstream. Additionally, filgrastim enhances the survival and function of mature neutrophils.

Pharmacodynamics

Filgrastim enhances the myeloid lineage of hematopoiesis, promoting the formation of neutrophils, which are crucial for the immune response against infections. It has a pharmacodynamic profile characterized by a rapid increase in circulating neutrophil counts, typically observed within 24 hours after administration. The duration of action is influenced by the dosing regimen and the patient's response to treatment.

Pharmacokinetics

Filgrastim is administered via subcutaneous or intravenous routes. It has a volume of distribution of approximately 0.1 L/kg and a clearance rate of about 0.6 mL/min/kg. The half-life of filgrastim is approximately 3 to 4 hours, but it may vary based on individual patient factors and dosing. The drug is not metabolized in the liver and is primarily eliminated via renal pathways. Dosage adjustments may be necessary in patients with renal impairment.

Contra-indications

• Hypersensitivity to filgrastim or any of its components
• Severe congenital neutropenia with history of severe or recurrent infections
• Malignant myeloid conditions or pre-malignant myeloid conditions
• Sickle cell disease with crisis

Adverse effects

• Arthralgia
• Headache
• Dyspnoea
• Leukocytosis
• Spleen abnormalities
• Cutaneous vasculitis
• Pulmonary infiltrates leading to acute respiratory distress syndrome
• Capillary leak syndrome
• Hypoxia
• Pulmonary oedema
• Acute febrile neutrophilic dermatosis

Precautions

• Monitor for signs of splenomegaly and rupture during treatment
• Full blood counts including differential white cell and platelet counts should be monitored
• Patients with a history of pulmonary infiltrates or pneumonia may be at higher risk for acute respiratory distress syndrome

Pregnancy

Manufacturers advise avoiding use due to potential toxicity observed in animal studies.

Breast-feeding

There is no evidence for safe use during breastfeeding, and manufacturers advise avoiding their use.

Storage

Store in a refrigerator (2°C to 8°C). Do not freeze. Protect from light.

Formulations

• Subcutaneous injection
• Intravenous infusion