antikoagulanta

Antikoagulants, or anticoagulants, are medications that reduce the blood’s ability to clot. They do not dissolve existing clots but prevent new clots from forming or growing, thereby lowering the risk of thrombosis and embolism in conditions such as atrial fibrillation, venous thromboembolism, and after certain surgeries.

Anticoagulants work at different points in the coagulation cascade. Direct oral anticoagulants (DOACs) include dabigatran, which inhibits thrombin, and rivaroxaban, apixaban, and edoxaban, which inhibit factor Xa. Vitamin K antagonists, such as warfarin, decrease the synthesis of several vitamin K–dependent clotting factors and require regular blood monitoring (INR) to keep dosing within a safe range. Parenteral anticoagulants include unfractionated heparin and low-molecular-weight heparins (e.g., enoxaparin, dalteparin), which accelerate the action of antithrombin; fondaparinux is another option. DOACs are typically taken by mouth with more predictable effects and less routine monitoring compared with warfarin, while heparins are usually given by injection and monitored by laboratory tests in hospital settings.

Common indications across these drugs include prevention of stroke in atrial fibrillation, treatment and prevention of deep vein thrombosis and pulmonary embolism, and prophylaxis of thromboembolism after many types of surgery. Warfarin remains the standard therapy for certain conditions, such as mechanical heart valves, where DOACs are not indicated. Safety considerations include a bleeding risk that varies by drug and patient factors, potential interactions with other medicines and diet (notably vitamin K with warfarin), and the need for monitoring or dose adjustments. Reversal strategies exist for major bleeding or overdose, including vitamin K for warfarin and specific antidotes for some DOACs.