Which of the following is a direct oral anticoagulant (DOAC) used in atrial fibrillation management?

• A. Apixaban
• B. Warfarin
• C. Heparin
• D. Enoxaparin

Answer: (A)

Direct oral anticoagulants are the modern choice for reducing stroke risk in atrial fibrillation because they provide predictable anticoagulation without routine blood monitoring. Apixaban is one of these DOACs; it inhibits factor Xa, helping to prevent the formation of clots.

In nonvalvular atrial fibrillation, apixaban (taken orally, usually twice daily) has strong patient outcomes data showing stroke and systemic embolism prevention that is comparable to warfarin but with a lower risk of major bleeding, especially intracranial hemorrhage. This makes it a preferred option for many patients who need long-term anticoagulation and want to avoid the burdens of regular INR checks and dietary restrictions that come with warfarin.

Warfarin is a vitamin K antagonist and requires regular INR monitoring and dose adjustments due to many food and drug interactions. Heparin and enoxaparin are parenteral anticoagulants used mainly in hospital settings or for short-term bridging; they’re not oral agents for chronic management of atrial fibrillation.