非格司亭 (Filgrastim)
**非格司亭 (Filgrastim)** 是一種重組人類顆粒球群落刺激因子 (G-CSF)，在獸醫學中用於刺激骨髓產生嗜中性白血球。 關鍵臨床重點： * **主要適應症：** 用於治療嚴重且危及生命的嗜中性白血球低下症（例如：繼發於小病毒感染、化療引起的骨髓抑制，或貓白血病病毒相關的週期性白血球低下）。 * **免疫原性風險：** 由於非格司亭源自人類 DNA，它在犬貓體內**具有高度免疫原性**。病患可能會產生中和抗體，不僅對抗外源性藥物，還會對抗自體產生的 G-CSF，導致嚴重、長期且可能致命的嗜中性白血球低下。 * **臨床策略：** 為了減少抗體形成，通常只在白血球最低谷的關鍵期進行短期的**「脈衝」治療**（3至5天）。 * **成本：** 治療費用非常昂貴，這通常限制了它在常規獸醫臨床上的使用。
作用機制: Filgrastim acts as a hematopoietic growth factor. * It binds specifically to **G-CSF receptors** located on the surface of myeloid progenitor cells in the bone marrow. * Receptor activation triggers intracellular signaling pathways (such as the **JAK/STAT pathway**) → stimulates the proliferation, differentiation, and activation of progenitor cells exclusively within the **neutrophil-granulocyte lineage**. * **Clinical Pearl:** In addition to increasing the absolute number of circulating mature neutrophils, filgrastim also enhances the functional capacity of these cells, including their phagocytic and bactericidal activities, thereby improving the patient's ability to fight off bacterial infections during periods of severe immunosuppression.
各物種劑量
- Adjunctive therapy of neutropenia (secondary to drug induced aplastic pancytopenia) · 5 micrograms/kg SC daily · SC · daily · Pulse therapy of no more than 5 days · To avoid autoantibody formation, pulse therapy is recommended.
- Neutropenia · 1-5 micrograms/kg SC daily · SC · daily · Pulse therapy of no more than 5 days · To avoid autoantibody formation, pulse therapy is recommended.
- Neutropenia · 100,000-500,000 IU (1-5 micrograms)/kg · SC · q24h · 3-5 days · Neutrophil counts typically rise within 24 hours.
- Neutropenia secondary to drug toxicity, infectious diseases, FeLV associated cyclic neutropenia or idiopathic causes · 5 micrograms/kg SC twice daily · SC · twice daily · Pulse therapy of no more than 5 days · Cost and/or development of antibodies usually limit usefulness to a few weeks, but often it is effective for acute or lifethreatening neutropenia.
- Neutropenia · 1-5 micrograms/kg SC daily · SC · daily · Pulse therapy of no more than 5 days · To avoid autoantibody formation, pulse therapy is recommended.
- Adjunctive therapy of neutropenia · 5 micrograms/kg SC daily until neutrophil count exceeds 3,000/mcl for 2 days · SC · daily · Until neutrophil count exceeds 3,000/mcl for 2 days (ideally ≤ 5 days) · To avoid autoantibody formation, pulse therapy is recommended.
- Neutropenia · 100,000-500,000 IU (1-5 micrograms)/kg · SC · q24h · 3-5 days · Neutrophil counts typically rise within 24 hours.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Hypersensitivity to filgrastim
- Patients that have previously developed antibodies to filgrastim with resultant neutropenia
不良反應
- Severe neutropenia (due to autoantibody formation against G-CSF)
- Myelofibrosis (theoretical/reported concern)
- Medullary histiocytosis (theoretical/reported concern)
- Injection site irritation
- Bone pain
- Splenomegaly
- Hypotension
藥物相互作用
- Antineoplastics · Avoid using filgrastim within 24 hours of administering antineoplastic agents that target rapidly proliferating cells, as it may exacerbate toxicity to the newly stimulated myeloid cells.
- Corticosteroids · May potentiate the release of neutrophils during G-CSF therapy. · moderate
- Lithium · May potentiate the release of neutrophils during G-CSF therapy. · moderate
- Cytotoxic Chemotherapy · Concurrent administration may increase the incidence of adverse effects. The stimulatory effects of G-CSF on haemopoietic precursors render them more susceptible to the effects of chemotherapy. · major
監測
- CBC with platelets, routinely (to monitor neutrophil response and detect potential antibody-induced neutropenia)
過量
Limited information is available regarding acute toxicity. Because of the high expense of the drug and its apparent limited acute toxic potential, clinically significant overdoses are considered unlikely. If an overdose occurs, monitor CBC closely and provide supportive care.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。