The development of novel oral anticoagulants that are effective alternatives to warfarin in non-valvular atrial fibrillation (AF) is a welcome advance. However, a variety of unresolved problems with their use, and not least with their cost, make it important to re-evaluate the use of warfarin as it will likely remain the anticoagulant of choice in South African patients with non-valvular AF for the foreseeable future. In this article, we review the correct clinical use of warfarin. Guidance is provided on commencing warfarin treatment, maintenance dosing, the recommended steps when temporary withdrawal of treatment is necessary, the management of bleeding, and the use of warfarin in chronic kidney disease. Techniques for changing from warfarin to one of the new oral anticoagulants and vice versa are included.
