Morbidly Obese Patient on Rivaroxaban Presents With Recurrent Upper Extremity Deep Vein Thrombosis: A Case Report.

A morbidly obese patient with history of deep vein thrombosis and pulmonary embolism was diagnosed with an acute left upper extremity deep vein thrombosis and started on rivaroxaban. Three months later, the patient returned with swelling in the right arm and was found to have a right brachial thrombosis. Anticoagulant therapy was switched to a low-molecular-weight heparin, and patient was discharged on enoxaparin along with an order to follow-up with a hematologist. Subanalyses from randomized controlled trials, pharmacokinetic/pharmacodynamic, and real-world studies suggest that rivaroxaban may be effective and safe in morbidly obese patients for primary and secondary prevention of venous thromboembolism. However, the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis does not recommend the use of direct-acting oral anticoagulants in this population. If used, drug levels should be monitored to guide the therapy. Due to the disparity in data to show efficacy and safety of rivaroxaban in morbidly obese subjects, the interpatient variability of rivaroxaban's effects in subjects, and the lack of defined therapeutic range for rivaroxaban drug concentration, rivaroxaban should be used cautiously in this population.