低分子量肝素 (達肝素, 依諾肝素)
**低分子量肝素 (LMWH)**，包含**達肝素 (dalteparin)**與**依諾肝素 (enoxaparin)**，是一種抗凝血劑，用於治療血栓栓塞併發症及高凝血症候群（例如：肺血栓栓塞、免疫介導性溶血性貧血 IMHA）。 > **臨床警告：** 其在瀰漫性血管內凝血 (DIC) 的使用具爭議性，目前已不再建議用於預防 DIC。肝素必須在有充足的**抗凝血酶 III (AT III)** 存在時才有效。 **臨床提示：** LMWH 具有比未分級肝素 (UFH) 更好的藥代動力學特性，其作用更可預測，但價格也相對昂貴許多。
作用機制: LMWH is an anticoagulant that inhibits **Factor Xa** and **thrombin**. * Compared with unfractionated heparin (UFH), LMWH has reduced anti-IIa activity relative to anti-Xa activity (ratio of anti-Xa to anti-IIa is 2-4:1 compared with UFH 1:1). * → At therapeutic doses, LMWH has minimal effect on aPTT. * → Therapeutic monitoring is performed by measuring **anti-Xa activity**.
各物種劑量
- Thromboembolic complications and hypercoagulable syndromes · Target anti-Factor Xa activity of 0.35-0.7 IU/ml · SC/IV · variable · As directed · Doses are controversial. Requires sufficient AT III. May use constant IV infusions.
- Thromboembolic complications and hypercoagulable syndromes · Target anti-Factor Xa activity of 0.35-0.7 IU/ml · SC/IV · variable · As directed · Cats appear to require higher dosages of LMWH to achieve proposed therapeutic targets.
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
給藥途徑
禁忌症
- Bleeding disorders
- Severe renal dysfunction
不良反應
- Haematoma formation (if administered IM)
- Haemorrhage (especially in thrombocytopenic patients or those with DIC)
藥物相互作用
- Aspirin · Can cause changes in coagulation status, increasing bleeding risk · major
- NSAIDs · Can cause changes in coagulation status, increasing bleeding risk · major
- ACTH · Heparin may antagonize ACTH · moderate
- Corticosteroids · Heparin may antagonize corticosteroids · moderate
- Insulin · Heparin may antagonize insulin · moderate
- Diazepam · Heparin may increase plasma levels of diazepam · moderate
- Antihistamines · May partially counteract the actions of heparin · minor
- Digoxin · May partially counteract the actions of heparin · minor
- Tetracyclines · May partially counteract the actions of heparin · minor
監測
- Anti-Factor Xa activity (target 0.35-0.7 IU/ml)
- aPTT (Activated partial thromboplastin time)
- PT (Prothrombin time)
- Fibrin degradation products
- Fibrinogen
- Clinical signs of bleeding
過量
If an overdosage occurs, **protamine** can be used as an antidote.
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。