Drug Guide
Filgrastim-ayow
Classification
Therapeutic: Colony-stimulating factor, Hematopoietic agent
Pharmacological: G-CSF (Granulocyte colony-stimulating factor)
FDA Approved Indications
- Reduce the incidence of febrile neutropenia in patients with non-myeloid malignancies receiving myelosuppressive chemotherapy
- Manage neutropenia occurring after bone marrow transplantation
Mechanism of Action
Filgrastim-ayow is a recombinant DNA granulocyte colony-stimulating factor that stimulates the proliferation, differentiation, and activation of neutrophil precursors in the bone marrow, leading to increased neutrophil counts.
Dosage and Administration
Adult: Dose varies based on clinical indication; typically 5 mcg/kg/day subcutaneously or intravenously, adjusted according to neutrophil count and patient response.
Pediatric: Dose is usually 5 mcg/kg/day subcutaneously; adjustments based on clinical response.
Geriatric: Same as adults; monitor for secondary effects, especially in older patients.
Renal Impairment: Use with caution; adjust dose if necessary, as pharmacokinetics may be altered.
Hepatic Impairment: No specific adjustments recommended.
Pharmacokinetics
Absorption: Rapid absorption after subcutaneous injection.
Distribution: Widely distributed; volume of distribution approximately 3.7 L.
Metabolism: cleared primarily by proteolytic enzymes and receptor-mediated clearance.
Excretion: Excreted unchanged in urine.
Half Life: Approximately 3.5 hours.
Contraindications
- Hypersensitivity to filgrastim or other PEG-filgrastim products.
Precautions
- Use with caution in patients with sickle cell anemia (risk of sickling crises), myelodysplastic syndrome, or blast-crisis in chronic myeloid leukemia. Monitor for splenic enlargement or rupture.
Adverse Reactions - Common
- Bone pain (Common)
- Arthralgia, myalgia (Common)
- Injection site reactions (Common)
Adverse Reactions - Serious
- Splenic rupture (Rare)
- Acute respiratory distress syndrome (ARDS) (Rare)
- S pleen enlargement, pain (Rare)
Drug-Drug Interactions
- Chemotherapy agents that cause myelosuppression may have additive effects.
- Cyclosporine may increase the risk of hematologic toxicity.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor complete blood counts frequently to assess neutrophil response. Watch for signs of splenic enlargement or pain.
Diagnoses:
- Risk for infection due to neutropenia.
- Pain related to bone marrow stimulation.
Implementation: Administer as prescribed, via subcutaneous injection. Educate patient about reporting signs of spleen enlargement, bone pain, or allergic reactions.
Evaluation: Assess response by monitoring neutrophil counts and infection rates.
Patient/Family Teaching
- Report signs of spleen enlargement (left upper quadrant pain, fullness).
- Report new or worsening bone pain.
- Understand the purpose of therapy and importance of adherence.
Special Considerations
Black Box Warnings:
- Splenic rupture is a rare but serious complication; patients should be advised to report any left upper abdominal pain or discomfort.
Genetic Factors: None specified.
Lab Test Interference: May cause transient increase in alkaline phosphatase levels.
Overdose Management
Signs/Symptoms: Bone pain, hypersensitivity, leukocytosis beyond therapeutic levels.
Treatment: Discontinue drug and provide supportive care; monitor blood counts closely.
Storage and Handling
Storage: Store in a refrigerator at 2°C to 8°C. Do not freeze.
Stability: Stable until the expiration date on the package.