Anticoagulants and antithrombotics prevent and treat thromboembolic events. Oral anticoagulants include warfarin (vitamin K antagonist — requires INR monitoring, multiple drug interactions) and DOACs (dabigatran — direct thrombin inhibitor; rivaroxaban, apixaban — direct factor Xa inhibitors), which do not require routine monitoring and have fewer interactions. Low-molecular-weight heparins (enoxaparin) are used for venous thromboembolism prophylaxis and treatment. Antiplatelet agents inhibit platelet aggregation: aspirin (irreversible COX-1 inhibition), clopidogrel (irreversible P2Y12 receptor inhibition) and ticagrelor (reversible P2Y12 inhibition — faster onset). Acenocoumarol is a coumarin alternative to warfarin available in Portugal. Therapeutic choice depends on indication (AF, stroke, VTE), renal function, bleeding risk and drug interactions. (Sources: DailyMed/FDA, EMC-UK/MHRA, Health Canada)
