Idraparinux for prevention of thromboembolism in atrial fibrillation

Idraparinux for prevention of thromboembolism in atrial fibrillation

Idraparinux is a synthetic analogue of the pentasaccharide moiety in heparin and low-molecular-weight heparin. Idraparinux specifically targets factor Xa. The half life is longer (80 hours) as it binds more tightly to antithrombin. Hence it is administered on a weekly basis. AMADEUS trial studied 4576 patients with atrial fibrillation to check for the non-inferiority with warfarin (2.5 mg weekly vs vitamin K antagonists @ INR 2 – 3). The trial was stopped because of excess clinically relevant bleeding (21 cases of intracranial hemorrhages for Idraparinux vs 7 for vitamin K antagonists). But there was less thromboembolism (18 vs 27). [1]

Reference

  1. Amadeus Investigators, Bousser MG, Bouthier J, Büller HR, Cohen AT, Crijns H, Davidson BL, Halperin J, Hankey G, Levy S, Pengo V, Prandoni P, Prins MH, Tomkowski W, Torp-Pedersen C, Wyse DG. Comparison of idraparinux with vitamin K antagonists for prevention of thromboembolism in patients with atrial fibrillation: a randomised, open-label, non-inferiority trial. Lancet. 2008.  26;371:315-21.