parnaparin

Parnaparin is a low molecular weight heparin (LMWH) used primarily as an anticoagulant to prevent and treat blood clots. It has a mean molecular weight of approximately 4.5 kDa and is characterized by a higher ratio of anti-factor Xa to anti-factor IIa activity compared to unfractionated heparin. Parnaparin is marketed under brand names such as Fluxum, Lowhepa, and Minihepa. It's administered subcutaneously, typically once daily, which is more convenient than the administration regimen of unfractionated heparin. The drug is used for preventing deep vein thrombosis, treating venous thromboembolism, and managing acute coronary syndromes. ## Mechanism of Action Parnaparin enhances the action of antithrombin III but has a higher ratio of anti-factor Xa to anti-factor IIa (antithrombin) activity compared to unfractionated heparin. It has less effect on platelet aggregation than heparin and doesn't significantly affect blood coagulation tests such as aPTT. ## Pharmacokinetics After subcutaneous administration, parnaparin reaches peak plasma levels of anti-Xa activity in about 3 hours. It has a plasma half-life of approximately 6 hours, with anti-Xa activity persisting in plasma for up to 20 hours after a single dose. The drug undergoes renal and hepatic metabolism and is primarily excreted in urine. ## Clinical Applications Parnaparin is used in: - Prevention of venous thromboembolism in surgical patients - Treatment of established deep vein thrombosis - Management of acute coronary syndromes - Treatment of chronic venous disorders Studies have shown that parnaparin is at least as effective as unfractionated heparin, with some data indicating superior efficacy in preventing composite endpoints of death, acute myocardial infarction, and myocardial revascularization in patients with unstable angina or acute ST-segment elevation myocardial infarction. ## Dosage Dosing varies by indication: - For general surgical procedures: 3200 units 2 hours before procedure, followed by 3200 units once daily - For higher-risk surgery or orthopedic patients: 4250 units 12 hours before procedure, followed by 4250 units 12 hours post-op and then once daily for 10 days - For thromboembolic disorders: 6400 units for 7-10 days ## Side Effects Common side effects include bleeding and injection site reactions. Parnaparin generally has better local tolerability than unfractionated heparin.

Brand names

FluxumLowhepaMinihepa

Other names

Parnaparin sodium