Nadroparin

Absorption

Absorption is linear. The bioavailability of nadroparin after subcutaneous administration is about 89%.

Toxicity

Osteopenia with extended use, skin necrosis, thrombocytosis, severe immunologically-mediated thrombocytopenia, eosinophilia (rare), calcinosis rarely occurs at the injection site, severe bleeding, transient elevation of liver transaminases.

Indications

Nadroparin is used for prophylaxis of thromboembolic disorders and general surgery in orthopedic surgery, treatment of deep vein thrombosis, prevention of clotting during hemodialysis and treatment of unstable angina and non-Q wave myocardial infarction.

Background

Nadroparin is a low molecular weight heparin (LMWH) which, when bound to antithrombin III (ATIII), accelerates the inactivation of factor II and factor Xa. Nadroparin halts the coagulation pathway by inhibiting the activation of thrombin (factor IIa) by factor Xa. The amplification of the fibrin clotting cascade is stopped once factors Xa and IIa are inactivated. It is derived from porcine sources and has a mean molecular size of 5000 daltons. Low molecular weight heparins are less effective at inactivating factor IIa due to their shorter length compared to unfractionated heparin.

Pharmacokinetics

Nadroparin is a low molecular weight heparin that is composed of a heterogeneous mixture of sulfated polysaccaride glycosaminoglycan chains. Th mean molecular weight is approximately 4300 daltons. The ratio of anti-Xa activity to anti-IIa is 3.5:1 whereas it is about 1:1 for heparin. Its use should be avoided in patients with a creatinine clearance less than 40mL/min. In these patients, unfractionated heparin should only be used. As for monitoring, active partial thromboplastin time (aPTT) will only increase at high doses of low molecular weight heparins (LMWH). Therefore, monitoring aPTT is not recommended. However, anti-Xa activity can be measured to monitor the efficacy of the LMWH.

Metabolism

Nadroparin is metabolized in the liver.