The use of anticoagulants for the treatment and prevention of venous thromboembolism in obese patients: implications for safety

Introduction: Obesity is a growing problem and is associated with a high risk of venous thromboembolism (VTE). Clinicians are increasingly challenged with prescribing adequate anticoagulants dosing while balancing the risk of bleeding.

Areas covered: In this narrative review, we address the safety of unfractionated heparin (UFH), low-molecular-weight heparins (LMWH), fondaparinux, warfarin and direct oral anticoagulants (DOAC) in obese patients.

Expert opinion: Obese patients have been under-represented in clinical trials and, therefore, the optimal dosing for both safety and efficacy in this subgroup remains unknown. Current data are based on pharmacokinetic studies in healthy subjects and small-scale cohort studies not adequately powered to detect differences in bleeding or thrombosis. Weight-based dosing of UFH and LMWH should be used over fixed dosing in most obese patients for VTE treatment and prophylaxis. For fondaparinux, increasing the dose with increasing weight is required for VTE treatment and consideration should be given to increasing the dose for VTE prophylaxis. Regarding the DOAC, they should be administered in fixed-dose regimens in the obese sub-population. Given the increasing prevalence of obesity and the associated increased risk of VTE, further studies are needed to establish the safety and efficacy of anticoagulation dosing regimens.