This article has a correction

Please see: Postgrad Med J 2014;90:575

Postgrad Med J 90:520-528 doi:10.1136/postgradmedj-2014-132605
  • Review

Non-vitamin K antagonist oral anticoagulants (NOACs): clinical evidence and therapeutic considerations

  1. Robert Storey1,2
  1. 1Department of Cardiology, Sheffield Teaching Hospitals NHS Foundation Trust, Northern General Hospital, Sheffield, UK
  2. 2Department of Cardiovascular Science, University of Sheffield, Medical School, Sheffield, UK
  1. Correspondence to Dr Karan Saraf, Department of Cardiology, Sheffield Teaching Hospitals NHS Foundation Trust, Northern General Hospital, Herries Road, Sheffield S5 7AU, UK; karansaraf{at}
  • Received 1 February 2014
  • Revised 16 July 2014
  • Accepted 18 July 2014
  • Published Online First 1 August 2014


Warfarin, a vitamin K antagonist, is the most widely used oral anticoagulant in the world. It is cheap and effective, but its use is limited in many patients by unpredictable levels of anticoagulation, which increases the risk of thromboembolic or haemorrhagic complications. It also requires regular blood monitoring and dose adjustment. New classes of drugs, non-vitamin K antagonist oral anticoagulants (NOACs), are now supported as alternatives to warfarin. Three NOACs are licensed: dabigatran, a direct thrombin inhibitor, and rivaroxaban and apixaban, antagonists of factor Xa. NOACs do not require routine blood monitoring or dose adjustment. They have a rapid onset and offset of action and fewer food and drug interactions. Current indications include treatment and prophylaxis of venous thromboembolism and prevention of cardioembolic disease in non-valvular atrial fibrillation. Effective antidotes are lacking and some caution must be used in severe renal impairment, but favourable trial evidence has led to their widespread adoption. Research is ongoing, and an increase in their use and indications is expected in the coming years.