Prediction models are the key to individualized drug therapy. Warfarin is a typical example of where pharmacogenetics could help the individual patient by modeling the dose, based on clinical factors and genetic variation in CYP2C9 and VKORC1. Clinical studies aiming to show whether pharmacogenetic warfarin dose predictions are superior to conventional initiation of warfarin are now underway. T...

AMI indicates acute myocardial infarction; INR, international normalized ratio. The goal of anticoagulant therapy with warfarin is to administer the lowest effective dose of the drug to maintain the target international normalized ratio (INR). Warfarin, a vitamin K antagonist, is an oral anticoagulant indicated for the prevention and treatment of venous thrombosis and its extension and the prev...

BACKGROUND The use of warfarin in older patients requires special consideration because of concerns with comorbidities, interacting medications, and the risk of bleeding. Several studies have suggested that warfarin may be underused or inconsistently prescribed in long-term care (LTC); no published systematic review has evaluated warfarin use for stroke prevention in this setting. This review w...

BACKGROUND AND OBJECTIVE The determination of warfarin, RS/SR- and RR/SS-warfarin alcohols in oral fluid may offer additional information to the INR assay. This study aimed to establish an optimized sampling technique providing the best correlation between the oral fluid and the unbound plasma concentrations of these compounds. MATERIALS AND METHODS Samples of non-stimulated and stimulated or...

Chronic oral anticoagulation with warfarin is difficult to maintain within the therapeutic range and requires frequent monitoring and dose adjustments. Variations in two genes, VKORC1 and CYP2C9, have been associated with variation in warfarin metabolism among individuals. Patients with CYP2C9*2 and *3 variants have longer times to dose stabilization and are at higher risk of serious and life-t...

BACKGROUND Warfarin is the most frequently used oral anticoagulant worldwide and it is the oral anticoagulant of choice in South Africa for reducing thrombosis-related morbidity and mortality. However, the safety and efficacy of warfarin therapy depends mainly on careful monitoring and maintenance of the international normalised ratio (INR) within an optimal therapeutic range. AIM The aim of ...

OBJECTIVES Warfarin is often used for ischemic stroke prevention in patients with atrial fibrillation (AF), but the factors affecting patient adherence to warfarin therapy have not been fully understood. METHODS A cross-sectional survey was conducted in AF patients undergoing warfarin therapy at least 6 months prior to the study. The clinical data collected using questionnaires by phone inter...

Wider use of oral anticoagulants has led to an increasing frequency of warfarin-related intracerebral hemorrhage (ICH). The high early mortality of approximately 50% has remained stable in recent decades. In contrast to spontaneous ICH, the duration of bleeding is 12 to 24 hours in many patients, offering a longer opportunity for intervention. Treatment varies widely, and optimal therapy has ye...

Introduction Cardioembolic stroke is associated with high morbidity and mortality, with an increased risk of recurrent stroke. Oral anticoagulation is highly effective in reducing the risk of stroke and mortality compared with placebo. Our study aimed to highlight the safety and efficacy of warfarin by analyzing the 20-year follow-up of patients on warfarin therapy. Methods A retrospective ob...

www.thelancet.com Vol 374 August 15, 2009 511 and for the rest by perceived increased bleeding risk. The last was based on inability to comply with monitoring by international normalised ratio, predisposition to falling or head trauma, persistent blood pressure above 160/100 mm Hg, previous serious bleeding on warfarin, severe alcohol misuse for more than 2 years, peptic ulcer disease, thromboc...