Pegfilgrastim

Indications

Pegfilgrastim is used for: Chemotherapy induced-neutropenia, Bone marrow stimulation

Adult Dose

Subcutaneous Chemotherapy-induced neutropenia, Myelosuppressive Chemotherapy Adjunct Indicated to decrease incidence of infection in patients with non-myeloid malignancies receiving myelosuppressive chemotherapy assoc with febrile neutropenia Adult: 6 mg as a single dose for each chemotherapy cycle, given at least 24 hr after cytotoxic chemotherapy.

Child Dose

Subcutaneous Prevention of Chemotherapy Induced Neutropenia <45 kg: 100 mcg/kg per chemotherapy cycle; not to exceed 6 mg/dose; do not administer in the period 14 days before and 24-72 hr after administration of cytotoxic chemotherapy >45kg: 6 mg SC once per chemotherapy cycle; do not administer in the period 14 days before and 24 hr after administration of cytotoxic chemotherapy

Renal Dose

Administration

Contra Indications

Hypersensitivity to Pegfilgrastim or filgrastim; or to any ingredients in the formulation.

Precautions

Splenic rupture (including fatal cases) or enlarged spleen have been reported following admin of Pegfilgrastim; patients who reported left upper abdominal or shoulder tip pain should be evaluated for development of splenomegaly or splenic rupture. Acute respiratory distress syndrome (ARDS) may occur; monitor patients for pulmonary symptoms e.g. cough, fever, lung infiltrates, or respiratory distress. Discontinue or withhold Pegfilgrastim in patients with confirmed ARDS. Caution in patients with existing sickle cell disorders; as severe sickle cell crisis may occur. Possibility of Pegfilgrastim acting as a growth factor for any tumor type cannot be excluded. Not approved for myeloid malignancies and myelodysplasia. Monitor platelet count and haematocrit regularly. Do not administer Pegfilgrastim during the 14 days before and 24 hr after chemotherapy admin due to the potential sensitivity of rapidly dividing myeloid cells to cytotoxic chemotherapy. Safety and efficacy in paediatric patients have not been established. Pregnancy and lactation.

Pregnancy-Lactation

Pregnancy Insufficient data available on use in pregnant women to establish whether there is a drug associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes Data from published studies in pregnant women exposed to filgrastim products have not established an association of filgrastim product use during pregnancy with major birth defects, miscarriage, or adverse maternal or fetal outcomes In animal studies, no evidence of reproductive/developmental toxicity occurred in offspring of pregnant rats that received cumulative doses of pegfilgrastim approximately 10 times recommended human dose (based on body surface area); in pregnant rabbits, increased embryolethality and spontaneous abortions occurred at 4 times the maximum recommended human dose simultaneously with signs of maternal toxicity Lactation Unknown whether pegfilgrastim is secreted in human milk Other recombinant G-CSF products are poorly secreted in breast milk, and G-CSF is not orally absorbed by neonates Caution should be exercised when administered to a nursing female

Interactions

Colony-stimulating factors such as Pegfilgrastim should not be given at the same time as cytotoxic chemotherapy due to the increased risk of myelosuppression.

Adverse Effects

Side effects of Pegfilgrastim : >10% Peripheral edema (12%), Asthenia (13%), Headache (16%), Vomiting (13%), Bone pain (31-57%), Myalgia (21%), Weakness (13%), Alopecia (15-72%), Pyrexia (23%) Frequency Not Defined Acute respiratory distress syndrome, Sickle cell crisis, Splenic rupture, Hyperuricemia, Elevated lactate dehydrogenase, Elevated alkaline phosphatase, Allergic reaction Potentially Fatal: Anaphylaxis.

Mechanism of Action

Pegfilgrastim is a covalent conjugate of filgrastim and monomethoxypolyethyleneglycol (PEG). It is a colony-stimulating factor which binds to specific cell surface receptors of haematopoietic cells, thereby stimulating proliferation, differentiation, commitment, and end cell functional activation. Pegfilgrastim has delayed renal clearance and prolonged half-life relative to filgrastim as a result of conjugation with PEG.