Can aspirin be used instead of warfarin? Stroke patients often ask their doctors: Doctor, I am already taking aspirin, is it necessary to take warfarin again? This is a question that concerns not only post-operative patients, but also many patients who need anticoagulation and antiplatelet after discharge from the hospital. The question of whether and when warfarin should be taken along with aspirin is not only a problem for many patients, but also for doctors who sometimes have difficulty in explaining the reasoning. This article provides some reference on whether patients with stroke and transient ischemic attack (TIA) should take anticoagulant drugs along with antiplatelet drugs. Some patients think that aspirin and warfarin are both anticoagulant drugs and that aspirin can replace the role of warfarin. In fact, the mechanism of action of warfarin and aspirin is different. Warfarin is an anticoagulant and aspirin is an antiplatelet agent, acting on different blood coagulation systems of the body. In some diseases, blood clots are formed due to a slowing of blood flow, and such clots caused by clotting abnormalities are mostly seen in the venous system, when warfarin is needed. In some diseases, platelet aggregation is the main cause of the clot, and aspirin is used to inhibit platelet aggregation. For patients with a history of stroke or TIA and atrial fibrillation, oral anticoagulation is recommended over both no antithrombotic therapy, aspirin therapy, and aspirin combined with clopidogrel, while anticoagulation is not currently recommended for patients with ischemic cerebrovascular disease. However, long-term anticoagulation is also indicated in certain patients with ischemic stroke of unknown origin, who often have both large foramen ovale and atrial septal tumors, and in whom the risk of recurrent stroke remains increased even with aspirin therapy. (Among the recommended antiplatelet therapy regimens, guidelines recommend clopidogrel or aspirin plus extended-release disopyramide over aspirin or cilostazol). Whether patients with a history of intracranial hemorrhage who also have an indication for oral warfarin can be safely treated is a difficult clinical decision. The following recommendations are made with reference to foreign guidelines: long-term antithrombotic therapy is usually not recommended for the prevention of ischemic stroke if the patient has a history of primary intracranial hemorrhage. Anticoagulation may still be considered in some patients with a low risk of intracranial hemorrhage (e.g., deep bleeding) and a very high risk of thrombosis, such as after mechanical flap implantation or in patients with an atrial fibrillation score greater than 4: at this time, close monitoring should be performed to minimize the risk of bleeding. For some patients, the current clinical alternative to warfarin is not aspirin, but new oral anticoagulants including dabigatran, rivaroxaban, and apixaban. Unlike warfarin, which affects the synthesis of multiple coagulation factors in the body, most of the new oral anticoagulants are thrombin or factor Xa antagonists, often acting on only one coagulation factor, which is more targeted and has a faster onset of action and metabolism, with relatively few influencing factors. It is not inferior to warfarin in reducing the risk of stroke, and does not increase the risk of bleeding, and even has a tendency to reduce, plus does not require frequent monitoring, and may have the trend of partially replacing warfarin in the future.