FOOD FOR THOUGHT: A CAUTIONARY TALE OF RIVAROXABAN FAILURE IN A MIDDLE-AGED MAN

ABSTRACT

SESSION TITLE Rare Cases of Nervous System and Thrombotic Complication Posters SESSION TYPE Case Report Posters PRESENTED ON 10/17/2022 1215 pm - 0115 pm INTRODUCTION: Rivaroxaban is a dose-dependent inhibitor of factor Xa. It is approved by the FDA to help reduce the risk of blood clots. Although bioavailability is not significantly affected at lower doses (80-100%), bioavailability at higher doses (≥15 mg) is as low as 66% when given without food [1] [3]. Here, we present a patient with poor oral intake who developed deep vein thrombosis (DVT) while on high dose Xarelto. CASE PRESENTATION Our patient was a 48-year-old male with a history of pulmonary embolism diagnosed two months prior to admission (on 20 mg rivaroxaban daily at home) and morbid obesity who presented with dyspnea, fever, and decreased appetite. His viral PCR was positive for COVID-19, and CT angiogram showed multifocal ground glass opacities but was negative for pulmonary embolism. He was severely hypoxic on room air and required noninvasive ventilatory support in the intensive care unit. He was treated with remdesivir, dexamethasone, and baricitinib. His food intake was extremely poor due to near continuous use of noninvasive ventilation and decreased appetite. A nasogastric (NG) tube was offered, but the patient declined and elected to continue diminished oral feedings. He was able to take all of his home medications including rivaroxaban during this time. On day four, clinical nutrition was consulted because he had 3% loss of body weight. On day seven, the patient developed a fever of 101.6° F. Ultrasound of his lower extremities revealed acute DVTs in his left popliteal vein, posterior tibial vein, and peroneal vein. His anticoagulation was switched to full-dose enoxaparin and a NG tube was placed. On day ten, he was intubated due to worsening hypoxia. Unfortunately, the patient deteriorated into multiorgan failure and died on day seventeen. DISCUSSION: The latest expert guidelines suggest that direct oral anticoagulants (DOAC) should be used over vitamin K antagonists (VKA) in patients with acute venous thromboembolism (VTE) due to lower rates of major bleeding and recurrent VTE as well as convenience. Although VKAs are preferred in situations with extreme weight and renal impairment, DOACs have been proven to be effective for the large majority of patients [2]. Unlike rivaroxaban, the bioavailabilities of other DOACs like apixaban, edoxaban, and dabigatran are all unaffected by food and should be preferred in patients with tenuous oral intake [3]. It is well known that COVID-19 can produce a hypercoagulable state. This factor, combined with our patient's predisposition to blood clots and poor appetite, ended up precipitating new onset VTEs in his left leg despite rivaroxaban therapy. CONCLUSIONS: In patients with decreased oral intake, DOACs other than rivaroxaban should be considered. Patients should be briefed on the importance of taking high dose rivaroxaban with food. Our goal is to bring awareness to providers about this significant pharmacodynamic property of rivaroxaban. Reference #1 Mueck W, Stampfuss J, Kubitza D, Becka M. Clinical pharmacokinetic and pharmacodynamic profile of rivaroxaban. Clin Pharmacokinet. 2014 Jan;53(1)1-16. doi 10.1007/s40262-013-0100-7. PMID 23999929;PMCID PMC3889701. Reference #2 Stevens SM, Woller SC, Baumann Kreuziger L, Bounameaux H, Doerschug K, Geersing GJ, Huisman MV, Kearon C, King CS, Knighton AJ, Lake E, Murin S, Vintch JRE, Wells PS, Moores LK. Executive Summary: Antithrombotic Therapy for VTE Disease Second Update of the CHEST Guideline and Expert Panel Report. Chest. 2021 Dec;160(6)2247-2259. doi 10.1016/j.chest.2021.07.056. Epub 2021 Aug 2. PMID 34352279. Reference #3 Lexicomp Online. Copyright © 1978-2022 Lexicomp, Inc. DISCLOSURES No relevant relationships by Rishika Bajaj No relevant relationships by Ann Hylton No relevant relationships by Roger McSharry No relevant relationships by Krupa Solanki