Overanticoagulation on coumarin anticoagulants

Abstract

Most of the extensive research on oral anticoagulant therapy has focussed on its pharmacological- and biochemical action, prothrombin time calibration, optimal therapeutic intensity and hemorrhagic complications. However, whlle the risks of overanticoagulation are clear, its treatment and determinants have received little attention. Therefore, the aim of this thesis was to study aspects of overanticoagulation on coumarin anticoagulants among outpatients of an anticoagulation clinic. Overanticoagulation was defined as an INR:>6.0, since at this INR-value the risk of hemorrhage sharply increases (28, 41). Chapter 2 relates to the treatment of overanticoagulation and describes the course of the INR in response to oral vitamin K1 in overanticoagulated patients. Chapter 3 concerns the incidence of and risk factors for overanticoagulation and includes five studies. Chapter 3.1 focusses on characteristics of antic