Rivaroxaban is recognized as an oral selective factor Xa inhibitor, meaning it precisely targets factor Xa, an essential enzyme in the coagulation cascade that plays a significant role in blood clot formation. By inhibiting factor Xa, Rivaroxaban effectively reduces thrombin production, which ultimately lowers the likelihood of clot formation. This mechanism makes it particularly useful in preventing conditions such as deep vein thrombosis (DVT), pulmonary embolism (PE), and in patients with atrial fibrillation to prevent stroke.
In contrast, Warfarin functions as a vitamin K antagonist that inhibits several clotting factors, including factors II, VII, IX, and X, but is not selective to factor Xa alone. Heparin is an injectable anticoagulant that mainly works by activating antithrombin III, leading to the inhibition of thrombin and factor Xa, but it does not qualify as an oral medication. Enoxaparin is a low molecular weight heparin that also inhibits factor Xa but is administered through injection, not orally. Therefore, Rivaroxaban stands out as the sole option that serves as an oral selective factor Xa inhibitor.