依諾肝素鈉
依諾肝素是一種**低分子量肝素 (LMWH)**，主要用於預防和治療血栓栓塞性疾病，如深靜脈血栓 (DVT)、肺栓塞 (PE) 和貓主動脈血栓栓塞 (FATE)。 與標準的未分級肝素 (UFH) 相比，依諾肝素等 LMWH 提供更可預測的藥代動力學特徵，並優先抑制凝血因子 Xa 而非凝血酶。這種選擇性作用意味著標準凝血測試（如 aPTT）不會顯著延長，從而降低了出血的可能性，但也使得監測需要更專業的檢驗。 **臨床要點：** * 雖然 LMWH 在人類中理論上比 UFH 更安全且更可預測，但它們在犬貓體內的快速清除需要頻繁的皮下給藥（通常每 6 小時一次）。 * 這種頻繁的給藥時間表，加上藥物的高昂成本，可能使獸醫學中的長期管理變得困難，特別是對於大型犬或馬。 * 最近針對貓的研究表明，抗 Xa 活性水平可能與實際的抗血栓功效並不完全相關，這增加了治療監測的複雜性。
作用機制: Enoxaparin exerts its anticoagulant effect by binding to and accelerating the activity of **antithrombin III (ATIII)**. * The enoxaparin-ATIII complex preferentially inhibits **Factor Xa** (→ blocking the conversion of prothrombin to thrombin in the coagulation cascade). * Because of its smaller molecular size compared to unfractionated heparin, enoxaparin has minimal impact on **thrombin (Factor IIa)**. * This selective anti-Xa activity prevents clot formation and extension without significantly altering standard clotting times (TT or aPTT).
各物種劑量
- Anticoagulant therapy · 1 mg/kg SC q12h · SC · q12h · Results in a measurable antithrombotic effect in healthy cats.
- Anticoagulant therapy · 1.5 mg/kg SC q6h · SC · q6h · Required to maintain a therapeutic target of anti-XA activity of 0.5-1 IU/mL.
- Anticoagulant therapy · 1.25 mg/kg SC q6h · SC · q6h · Current recommendations based on research in healthy cats.
- Anticoagulant therapy · No published dosage recommendation at the time of writing. · SC · q24h · Study demonstrated drug has similar activity as in humans and once daily SC injections may be useful.
- Anticoagulant therapy · 0.8 mg/kg SC q6h · SC · q6h · Appears to effectively and consistently maintain therapeutic levels of anti-Xa in normal dogs.
- Anticoagulant therapy · 0.8-1 mg/kg SC q6-8h · SC · q6-8h
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 enoxaparin, other LMWHs, heparin, or porcine products
- Intramuscular (IM) or Intravenous (IV) administration (must be given SC only)
不良反應
- Hemorrhage (unlikely but possible)
- Injection site hematoma
- Anemia
- Thrombocytopenia
- Nausea
- Fever
- Asymptomatic, reversible increases in AST or ALT
藥物相互作用
- Warfarin (Oral Anticoagulants) · Increased risk for hemorrhage
- Aspirin · Increased risk for hemorrhage
- Clopidogrel · Increased risk for hemorrhage
- Thrombolytic Agents · Increased risk for hemorrhage
監測
- CBC (with platelet count); baseline and ongoing during therapy
- Urinalysis
- Stool occult blood test
- Factor Xa activity (useful if bleeding occurs or patient has renal dysfunction)
- Note: Routine coagulation tests (aPTT, PT) are usually insensitive measures of activity and usually not warranted
過量
Overdosage may lead to **hemorrhagic complications**. If treatment is necessary, **protamine sulfate** may be administered via slow IV as an antidote. * **Dose:** 1 mg of protamine sulfate can inhibit the effects of 1 mg of enoxaparin.
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。