Arixtra, also known as Fondaparinux sodium, is a drug that inhibits Factor X, a protein involved in blood clotting. It is used to prevent deep vein thrombosis (DVT) in patients who have undergone certain surgical procedures and to treat DVT or acute pulmonary embolism when combined with warfarin.

Many clinical studies have demonstrated the efficacy and safety of fondaparinux, highlighting its value in clinical practice. Fondaparinux offers various advantages, such as its chemical synthesis, minimal risk of contamination, 100% bioavailability when administered subcutaneously, immediate onset of action, prolonged half-life, direct renal excretion, fewer adverse reactions compared to direct oral anticoagulants, and usefulness in situations where oral anticoagulants are not permitted or in patients who experience intolerance to LMWHs.

Adverse events: 

Bleeding complications are the most commonly reported adverse reactions of fondaparinux sodium. Subcutaneous injection of the drug may cause mild local irritation such as injection site bleeding, rash, and pruritus.

Mechanism of action: 

Fondaparinux sodium exerts its antithrombotic effects through selective inhibition of Factor Xa, mediated by antithrombin III (ATIII). When it binds to ATIII, fondaparinux sodium enhances the inherent neutralizing ability of ATIII against Factor Xa by approximately 300-fold. This neutralization of Factor Xa disrupts the coagulation cascade, thereby preventing thrombin formation and inhibiting the development of blood clots.