In non-valvular atrial fibrillation, which anticoagulant is commonly used?

• A. Warfarin
• B. Rivaroxaban
• C. Aspirin
• D. Heparin

Answer: (B)

Stroke prevention in non-valvular atrial fibrillation is best achieved with direct oral anticoagulants, such as rivaroxaban. These agents directly inhibit factor Xa, reducing thrombin generation and clot formation with a predictable effect and without the need for routine INR monitoring. This makes long-term outpatient therapy easier to manage compared with warfarin, which requires regular blood tests, dose adjustments, and vigilance for drug–diet interactions. Among the DOACs, rivaroxaban is a commonly prescribed option due to its convenient dosing and demonstrated effectiveness in preventing strokes and systemic embolism with a comparable safety profile to warfarin in many patients. Dose considerations include adjustments for renal function, and it’s important to avoid use in patients with mechanical heart valves or certain types of significant valvular disease. While aspirin offers some protection, it is less effective than anticoagulation for stroke prevention in this setting, and parenteral heparin is typically reserved for inpatient use or bridging rather than chronic outpatient therapy.