The anticoagulant warfarin has >30 million prescriptions per year in the United States. Doses can vary 20-fold between patients, and incorrect dosing can result in serious adverse events. Variation in warfarin pharmacokinetic and pharmacodynamic genes, such as CYP2C9 and VKORC1, do not fully explain the dose variability in African Americans. To identify additional genetic contributors to warfar...

Skin reactions associated with oral coumarin-derived anticoagulants are an uncommon occurrence. Leukocytoclastic vasculitis (LV) is primarily a cutaneous small vessel vasculitis, though systemic involvement may be encountered. We report 4 patients with late-onset LV probably due to warfarin. All 4 patients presented with skin eruptions that developed after receiving warfarin for several years. ...

Fetal warfarin syndrome (FWS) or warfarin (coumadin) embryopathy is a rare condition as a result of fetal exposure to maternal ingestion of warfarin during pregnancy. A male infant, whose mother was treated with the anticoagulant (warfarin) because of a mechanical heart valve replacement after rheumatic heart disease, presented with signs of warfarin embryopathy. The facial dysmorphism included...

OBJECTIVES To quantify the influence of physicians' experiences of adverse events in patients with atrial fibrillation who were taking warfarin. DESIGN Population based, matched pair before and after analysis. SETTING Database study in Ontario, Canada. PARTICIPANTS The physicians of patients with atrial fibrillation admitted to hospital for adverse events (major haemorrhage while taking 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...

Warfarin is a commonly used anticoagulant for the primary or secondary prevention of thrombotic events.1 Tremendous inter-individual variability in warfarin dosing is apparent, necessitating frequent monitoring via the international normalized ratio (INR). The most feared complication of warfarin therapy is major bleeding, and the risk of this problem increases when the INR exceeds 4.0.2 Critic...

For most warfarin indications, the target maintenance international normalised ratio (INR) is 2-3. Risk factors for bleeding complications with warfarin use include age, history of past bleeding and specific comorbid conditions. To reverse the effects of warfarin, vitamin K(1) can be given. Immediate reversal is achieved with a prothrombin complex concentrate (PCC) and fresh frozen plasma (FFP)...

the Sand R-enantiomer, has been used as an anticoagulant agent. The anticoagulant activity of S-warfarin is 3—5 times as great as that of R-warfarin. Warfarin is highly bound to Site I, a warfarin binding site, in the human serum albumin (HSA) molecule (97—99%). The unbound fraction of warfarin is increased by the displacement of the binding site caused by the coadministration of several drugs....

The effects of genetic variants on warfarin dosing vary among different ethnic groups, especially in the Chinese population. The objective of this study was to recruit patients through a rigorous experimental design and to perform a comprehensive screen to identify gene polymorphisms that may influence warfarin dosing in northern Han Chinese patients with mechanical heart valve replacement. Con...

OBJECTIVE  To study the effectiveness and safety of the non-vitamin K antagonist oral anticoagulants (novel oral anticoagulants, NOACs) dabigatran, rivaroxaban, and apixaban compared with warfarin in anticoagulant naïve patients with atrial fibrillation. DESIGN  Observational nationwide cohort study. SETTING  Three Danish nationwide databases, August 2011 to October 2015. PARTICIPANTS  61...