CVM Cardiovascular Medicine 1664-204X 1664-2031 EMH Schweizerischer Ärzteverlag AG Farnsburgerstrasse 8 CH-4132 Muttenz 02204 10.4414/cvm.2022.02204 Case report Thrombosis & Platelets Monitoring of apixaban in a super-obese patient: impact of renal failure and topical application of econazole Cadart Olivier cadart.olivier@laposte.net FRANCE Mouton Christine CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux Michelet Marie CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux Bosc Laurène CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux Pupier Emilie CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux Monsaingeon-Henry Maud CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux Cherifi Blandine CHU de Bordeaux: Centre Hospitalier Universitaire de Bordeaux 01 09 2022 25 05 0 0 Copyright: EMH Schweizerischer Ärzteverlag AG 2022 EMH Schweizerischer Ärzteverlag AG "Cardiovascular Medicine" is an open access publication of EMH published in accordance with the terms of the Creative Commons licence attribution - NonCommercial - NoDerivatives 4.0 International. You are free to share, copy and redistribute the material in any medium or format under the following terms: Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. NonCommercial — You may not use the material for commercial purposes. NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material. "Non-commercial" means not primarily intended for or directed towards commercial advantage or monetary compensation. The incorporation of publications in commercial products, the use of publications to advertise for commercial products or services and any other usage that directly or indirectly pursues commercial interests is subject to the express previous consent of the publishing house as part of a written agreement. Please send us your request in writing. Exact indication of the publication from which you would like to reproduce material and detailed information about its intended use help to facilitate and expedite request processing.

Background: Direct oral anticoagulants (DOACs) are considered advantageous compared to vitamin K antagonists in eligible atrial fibrillation patients but the efficacy and the safety of DOACs are not well defined in the morbidly obese population. Methods: We report the case of a 59-year-old woman patient (160 cm, 188 kg, BMI 73.5 kg/m²) with multiple comorbidities including non-valvular atrial fibrillation anticoagulated with apixaban 5mg twice a day who was admitted to our hospital because of acute renal failure. Results: We report changes in apixaban concentration levels over the course of management. Apixaban concentrations were quantified using Liquid Anti-Xa HemosIL® Werfen. Table and Figure report apixaban concentration according to therapeutic modifications and renal function. Conclusion: This case illustrates the interest of measuring occasionally the DOAC concentration in case of intercurrent pathology, in particular acute renal insufficiency, or in case of using topic drugs medication known to interact with DOAC by the oral route. Plasma DOAC measurement would be also interesting in case of co-medication unknown for drug interaction. This case also shows an effective and safe anticoagulation by DOAC in a superobese patient.