The complexity of treatment with warfarin

Maintaining a patient within a therapeutic international normalized ratio (INR) is the main aim of treatment with warfarin. Anticoagulation above or below the therapeutic window may result in bleeding or thrombosis respectively. This is made more complex by the numerous factors that may affect warfarin management including other drugs, diet and disease. This review aims to highlight factors that may affect therapy with oral anticoagulants (Figure 1). A sound knowledge of such factors ensures safe administration of warfarin.peer-reviewe