達貝泊汀α
達貝泊汀α（Darbepoetin alfa）是一種合成的長效紅血球生成刺激劑（ESA）。它是透過重組DNA技術在中國倉鼠卵巢細胞中生產的165個胺基酸蛋白質。 **臨床要點**：與依泊汀α（epoetin alfa）相比，達貝泊汀含有兩個額外的N-連接碳水化合物鏈。這種結構修飾增加了其分子量，並顯著提高了其代謝穩定性和半衰期，從而允許較低頻率的給藥（例如，每週一次而不是每週三次）。 在獸醫學中，它主要用於標示外使用（off-label），以控制犬貓因慢性腎病（CKD）引起的非再生性貧血。理論上，額外的碳水化合物屏障可能使其免疫原性低於依泊汀α，從而潛在地降低純紅血球再生不良（PRCA）的風險，儘管這在獸醫病患中尚未得到證實。
作用機制: Darbepoetin alfa mimics endogenous erythropoietin by binding to the **erythropoietin receptor (EpoR)** on the surface of erythroid progenitor stem cells in the bone marrow. * Binding induces receptor dimerization → activates the **JAK2/STAT5** intracellular signaling pathway. * This cascade → inhibits apoptosis of progenitor cells → stimulates their proliferation and differentiation into mature **red blood cells (RBCs)**. * The increased RBC mass subsequently raises the packed cell volume (PCV) and improves tissue oxygenation.
各物種劑量
- Anemia of chronic kidney disease · 0.45 micrograms/kg · SC/IV · once weekly · Initial human dose. Adjust using clinical judgment and careful monitoring. Alternatively, convert from epoetin alfa: Total weekly dose of epoetin in Units divided by 200 = once weekly dose in micrograms darbepoetin.
- Anemia of chronic kidney disease · 0.45 micrograms/kg · SC/IV · once weekly · Initial human dose. Adjust using clinical judgment and careful monitoring. Alternatively, convert from epoetin alfa: Total weekly dose of epoetin in Units divided by 200 = once weekly dose in micrograms darbepoetin.
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
- Patients with documented anti-rHuEPO antibodies
- Uncontrolled hypertension
- Hypersensitivity to darbepoetin or excipients in the formulation
不良反應
- Anti-rHuEPO antibody formation leading to pure red blood cell aplasia (PRCA)
- Hypertension
- Seizures
- Iron deficiency (due to rapid RBC production depleting iron stores)
藥物相互作用
- Androgens · May increase the sensitivity of erythroid progenitors (interaction has been used for therapeutic effect with epoetin)
- Desmopressin · Can decrease bleeding times when used concurrently with erythropoietin agents
監測
- PCV/Hematocrit (check before each re-dosing)
- Iron stores (supplement with iron if necessary)
- Blood pressure
過量
Little information is available in veterinary species. In humans, therapeutic dosages of up to 8 micrograms/kg every week for 12 weeks have been administered. Polycythemia (excessive red blood cells) is possible with overdosage, and therapeutic phlebotomy may be required to reduce blood viscosity.
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。