Anisindione is primarily used as an anticoagulant to prevent the formation of blood clots. It works by inhibiting vitamin K-dependent clotting factors in the liver, thereby prolonging the time it takes for blood to clot. It is prescribed for patients at risk of thromboembolic disorders, such as deep vein thrombosis, pulmonary embolism, and stroke prevention in individuals with atrial fibrillation. Due to its narrow therapeutic index and potential for drug interactions, regular monitoring of coagulation parameters is required during treatment. Anisindione is typically reserved for cases where other anticoagulants are not suitable, given the availability of newer agents with more predictable effects.