From the Guidelines
Enoxaparin works by inhibiting Factor Xa with a minimal effect on thrombin.
Mechanism of Action
- Enoxaparin is a low-molecular-weight heparin (LMWH) with a 4:1 ratio of Factor Xa to thrombin activity 1.
- It has greater activity against Factor Xa than thrombin, which is a key component in the coagulation cascade 1.
- The mechanism of action of enoxaparin is related to its ability to inhibit Factor Xa, which is involved in the production of thrombin 2.
- As a result, enoxaparin has a more predictable anticoagulant effect compared to unfractionated heparin, due to its reduced binding to plasma proteins and cells 1, 3.
Pharmacokinetics
- Enoxaparin has a longer half-life than unfractionated heparin, which is further delayed in patients with renal dysfunction 1.
- It is cleared renally, which can lead to a prolonged biological half-life in patients with renal failure 2, 3.
- The predictable pharmacokinetics of enoxaparin make it a useful option for anticoagulation therapy, as it does not require laboratory monitoring of activity 2.
From the Research
Mechanism of Action of Enoxaparin
The mechanism of action of enoxaparin is primarily based on its ability to inhibit factor Xa and thrombin IIa through antithrombin III, an endogenous inhibitor 4. Key aspects of its mechanism include:
- Inhibition of tissue factor-mediated prothrombinase assembly and activity by factor-Xa neutralization 5
- Binding to and increasing the activity of antithrombin III, resulting in the inhibition of prothrombinase-mediated thrombin generation and direct thrombin generation by binding to factor Xa and thrombin factor IIa 6
- Prevention of platelet surface prothrombinase assembly and inactivation of platelet prothrombinase activity, leading to reduced thrombin generation 5
Pharmacological Properties
Enoxaparin has several pharmacological properties that contribute to its effectiveness, including:
- Greater bioavailability and longer half-life compared to unfractionated heparin, allowing for less frequent subcutaneous administration 7
- Higher anti-Xa activity than unfractionated heparin, which is important for its antithrombotic effects 5
- A more stable and predictable anticoagulation profile, allowing for fixed dosing without the need for monitoring 4
Clinical Applications
Enoxaparin has been shown to be effective in a variety of clinical applications, including: