Comparative Study on the Antithrombotic Efficacy of Four Low-Molecular-Weight Heparins in Three Different Models of Experimental Venous Thrombosis

1991 ◽  
Vol 21 (2) ◽  
pp. 91-97 ◽  
Author(s):  
Manuel Monreal ◽  
Pierre Silveira ◽  
Luis Monreal ◽  
Jasone Monasterio ◽  
Anna María Angles ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Comparative Study ◽  
Venous Thrombosis ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Antithrombotic Efficacy

Heparin and low-molecular-weight heparin

2008 ◽  
Vol 99 (11) ◽  
pp. 807-818 ◽  
Author(s):  
Barbara Mulloy ◽  
Trevor Barrowcliffe ◽  
Elaine Gray
Keyword(s):  
Molecular Weight ◽  
Venous Thrombosis ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Clinical Status ◽  
Mechanisms Of Action ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Prevention And Treatment

SummaryHeparin is one of the oldest biological medicines, and has an established place in the prevention and treatment of venous thrombosis. Low-molecular-weight heparins (LMWH) have been developed by several manufacturers and have advantages in terms of pharmacokinetics and convenience of administration. They have been shown to be at least as effective and safe as unfractionated heparin and have replaced the latter in many indications. In this article the chemistry, mechanisms of action, measurement of anticoagulant activities, and clinical status of heparin and LMWH are reviewed.

scholarly journals Anticoagulation in Patients with Liver Cirrhosis (Literature Review)

2019 ◽  
Vol 4 (2) ◽  
pp. 23-28
Author(s):  
E. S. Eniseeva
Keyword(s):  
Atrial Fibrillation ◽  
Molecular Weight ◽  
Liver Cirrhosis ◽  
Venous Thrombosis ◽  
Vitamin K Antagonists ◽  
Coagulation Cascade ◽  
Low Molecular Weight ◽  
Thromboembolic Complications ◽  
Low Molecular Weight Heparins ◽  
Increased Risk

Liver cirrhosis is accompanied by complex hemostatic disorders with an increase in the risk of both hemorrhagic and thrombotic complications. Reduced coagulation protein synthesis, such as factors II, VII, IX, X and thrombocytopenia are associated with an increased risk of bleeding. Reducing the synthesis of such anticoagulants as protein C, protein S, antithrombin III is accompanied by increased generation of thrombin, which leads to procoagulant status, increased risk of venous thrombosis, pulmonary embolism, and portal vein thrombosis. Activation of the coagulation cascade increases the risk of thrombosis, and also plays an important role in liver damage, contributing to the progression of fibrosis. Cirrhosis increases the risk of thromboembolic complications of atrial fibrillation.Anticoagulants are necessary for the prevention of thrombosis and thromboembolic complications. However, there are no large prospective studies. There is insufficient data on the safety of anticoagulant therapy in cirrhosis. There are difficulties in monitoring anticoagulation in the application of vitamin K antagonists and low molecular weight heparins.The review presents the available data on the use of warfarin, unfractionated heparin, low molecular weight heparins and direct oral anticoagulants in patients with liver cirrhosis, indicating the need for prevention of venous thrombosis in patients with risk factors, the possibility of preventing decompensation of cirrhosis, reducing the frequency of cardioembolic strokes in patients with atrial fibrillation.

PHARMACOLOGIC INEQUIVALENCE OF LOW MOLECULAR WEIGHT HEPARINS

1987 ◽  
Author(s):  
J Fareed ◽  
J M Walenga ◽  
D Hoppensteadt ◽  
R N Emanuele ◽  
A Racanell
Keyword(s):  
Molecular Weight ◽  
Animal Models ◽  
Comparative Study ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
In Vivo Test ◽  
In Vitro Effects

Compared to unfractionated heparin, low molecular weight heparins (LMWHs) have been found to exhibit marked variations in in vitro effects due to variations in molecular weight and structure. Moreover, when the in vitro potency of these agents is equally adjusted bypharmacopeial assay (current and proposed) wide variations in the in vivo responses have been noted. These variations were strongly dependent on the route of administration. Utilizing defined animal models, a systematic comparative study of the in vivo responses of seven commercial LMWHs was undertaken. Choay Fraxiparine (CY 216} Choay CY 222, NovoLHN, Kabi Fragmin, Opocrin 2123 (OP), Hepar RD 11885 (RD), Pharmuka Enoxaparin (PK) and Choay porcine mucosal heparin (PMH) were tested in identical settings at equigravimetric dosages. The graded results are given in the following.Wide variations in the in vivo pharmacologic and toxicity responseswere noted suggesting that different LMWHs are not bioequivalent at equigravimetric levels. When these responses were expressed in anti-factor Xa or pharmacopeial potency, these differences were further magnified. The clinically reported dosimetric and safety problems may be minimized by profiling LMWHs in defined in vivo test systems to optimize their safety/efficacy ratio.

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