Which of the following is NOT considered an anticoagulant?

Sildenafil is not considered an anticoagulant because it is primarily used as a phosphodiesterase type 5 (PDE5) inhibitor, mainly prescribed for the treatment of erectile dysfunction and pulmonary arterial hypertension. Its mechanism of action involves increasing blood flow by relaxing blood vessels, rather than affecting blood coagulation pathways.

Anticoagulants, on the other hand, are medications specifically designed to prevent blood clot formation. Coumadin (warfarin), Xarelto (rivaroxaban), and Eliquis (apixaban) are examples of anticoagulants that work through various mechanisms to inhibit coagulation factors in the blood, thereby reducing the risk of thromboembolic events. Coumadin is a vitamin K antagonist, while the other two are direct oral anticoagulants that inhibit specific factors in the coagulation cascade.