Anticoagulating obese patients in the modern era.

The prevalence of obesity has increased substantially over recent years. Clinicians are increasingly being challenged with making uncertain anticoagulant dosing decisions, as the optimal dosing strategy for most anticoagulants in the obese patient population remains unknown. Research published to date suggests that the clearance of anticoagulants increases with weight. As obesity is associated with an increased risk of venous thromboembolism and arterial disease, there is an urgent need to establish appropriate anticoagulation regimens for this patient group. Research studies applying the method of pharmacokinetic-pharmacodynamic modelling and simulation could establish an appropriate evidence base and provide direction and reassurance to prescribing clinicians.

New anticoagulants for prevention and treatment of venous thromboembolism.

Venous thromboembolism (VTE) is a major public health issue, with a high incidence in hospitalised patients. Furthermore, many VTE events are preventable with appropriate thromboprophylaxis. Medical thromboprophylaxis usually comprises heparins, while warfarin has been the mainstay of long term anticoagulation for many years. Both drugs are limited by their narrow therapeutic index and the need for regular monitoring. The introduction of low molecular weight heparins and fondaparinux has overcome some of these shortfalls but their use remains restricted by requisite parenteral administration. There is a clear need for new anticoagulants with predictable pharmacokinetics and anticoagulant effect. To this end, 2 new agents; dabigatran and rivaroxaban, have recently been licensed for use in orthopaedic thromboprophylaxis. This review discusses the limitations of traditional anticoagulants, and summarises the development and clinical studies pertaining to the use of 3 new targeted anticoagulants: idraparinux, rivaroxaban and dabigatran in VTE, in addition to the limitations of these novel agents.