LMW heparins include enoxaparin, dalteparin, and tinzaparin. Unfractionated heparin and LMW heparin inhibit both factor Xa and thrombin; the effect of LMW heparins on thrombin is less than that of unfractionated heparin. Fondaparinux is a synthetic pentasaccharide based on the minimal antithrombin-binding region of heparin that inhibits factor Xa. LMW heparins, unfractionated heparin, and fondaparinux inhibit clotting factors by binding to antithrombin. Oral direct factor Xa inhibitors include apixaban, rivaroxaban, and edoxaban. Parenteral direct thrombin inhibitors include argatroban and lepirudin. Oral direct thrombin inhibitors include dabigatran. Coagulation factors are shown as Roman numerals. Only the activated forms (with the suffix "a") are shown for simplicity. Thrombin is also known as factor IIa.
