Agents which slow ;/or break down blood clot formation in up to 3 different ways (they do not decrease blood viscosity; thickness.) (1) some inhibit platelet function (e.g. Aspirin, clopidogrel, etc.). (2) others interfere with some of the clot forming proteins (warfarin, dabigatran, rivaroxaban, etc.), (3) others stimulate the blood clot destruction proteins (heparins, enoxaparin, etc.).