Brands, Medical Use, Clinical Data
Drug Category
- Fibrinolytic Agents
- Anticoagulants
- Heparins
Dosage Forms
- Solution (for subcutaneous injection)
Brands / Synonyms
Clexane; Enoxaparin sodium; LMWH
; Lovenox; Lovenox HP; Low Molecular Weight Heparin
Indications
For the prophylaxis of deep vein thrombosis, which may lead to pulmonary embolism, and also for the prophylaxis of ischemic complications of unstable angina and non-Q-wave myocardial infarction, when concurrently administered with aspirin.
Pharmacology
Enoxaparin is a highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Enoxaparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Enoxaparin is a well known and commonly used anticoagulant which has antithrombotic properties. Enoxaparin inhibits reactions that lead to the clotting of blood and the formation of fibrin clots both in vitro and in vivo. Enoxaparin acts at multiple sites in the normal coagulation system. Small amounts of enoxaparin in combination with antithrombin III (enoxaparin cofactor) can inhibit thrombosis by inactivating activated Factor X and inhibiting the conversion of prothrombin to thrombin. Once active thrombosis has developed, larger amounts of enoxaparin can inhibit further coagulation by inactivating thrombin and preventing the conversion of fibrinogen to fibrin. Enoxaparin also prevents the formation of a stable fibrin clot by inhibiting the activation of the fibrin stabilizing factor.
Mechanism of Action
The mechanism of action of enoxaparin is antithrombin-dependent. It acts mainly by accelerating the rate of the neutralization of certain activated coagulation factors by antithrombin, but other mechanisms may also be involved. The antithrombotic effect of enoxaparin is well correlated to the inhibition of factor Xa. Enoxaparin interacts with Antithrombin III, Prothrombin and Factor X.
Absorption
Mean absolute bioavailability of enoxaparin, after 1.5 mg/kg given subcutaneously, based on anti-Factor Xa activity is approximately 100% in healthy volunteers.
Toxicity
Mouse, median lethal dose greater than 5000 mg/kg. Another side effect is heparin induced thrombocytopenia (HIT syndrome). HIT is caused by an immunological reaction that makes platelets form clots within the blood vessels, thereby using up coagulation factors.
Biotrnasformation / Drug Metabolism
Hepatic.
Contraindications
Lovenox Injection is contraindicated in patients with active major bleeding, in patients with thrombocytopenia
associated with a positive in vitro test for anti-platelet antibody in the presence of enoxaparin sodium, or
in patients with hypersensitivity to enoxaparin sodium. Patients with known hypersensitivity to heparin or pork
products should not be treated with Lovenox Injection or any of its constituents.
Drug Interactions
Unless really needed, agents which may enhance the risk of hemorrhage should be discontinued prior to initiation
of Lovenox Injection therapy. These agents include medications such as: anticoagulants, platelet inhibitors including
acetylsalicylic acid, sali-cylates, NSAIDs (including ketorolac tromethamine), dipyridamole, or sulfinpyrazone. If
co-administration is essential, conduct close clinical and laboratory monitoring.
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