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Granulocyte Colony-Stimulating Factor

Filgrastim (G-CSF)

Brand names: Neupogen, Zarzio, Nivestim

Filgrastim is a recombinant granulocyte colony-stimulating factor (G-CSF) used to reduce the duration of neutropenia and risk of febrile neutropenia, and to mobilise stem cells.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It binds G-CSF receptors to stimulate proliferation, differentiation and release of neutrophils from the bone marrow, raising the circulating neutrophil count.

Prescribing in practice

  • Splenic rupture has been reported, so left upper abdominal or shoulder-tip pain must be investigated promptly.
  • It can cause bone pain and, rarely, serious pulmonary or capillary leak reactions that require monitoring.
  • It should not be given concurrently with cytotoxic chemotherapy within the period around dosing as specified in the SPC.

Monitoring

Monitor the full blood count, including neutrophils and platelets, to guide therapy and watch for splenic enlargement and pulmonary symptoms.

Counselling the patient

  • Bone or muscle aches are common and can usually be eased with simple analgesia.
  • Report severe upper-left abdominal or shoulder pain, or breathing difficulty, urgently.
  • Injection technique and storage in the fridge will be explained for home use.

Evidence & guidelines

G-CSF reduces febrile neutropenia and supports stem-cell mobilisation, with use guided by NICE and specialist oncology and haematology protocols.

Reference: ASCO guidelines; ESMO guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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