Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 11 2 2024 10 29 256 258 Hossein Karballaei Mirzahosseini Department of Clinical Pharmacy, School of Pharmacy, Semnan University of Medical Sciences, Semnan, Iran. Parinaz Shahriari Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. Ehsan Yousefi-Mazhin Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. Atabak Najafi Department of Anesthesiology and Critical Care Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. Amirmahdi Mojtahedzadeh Faculty of Medicine, Semmelweis University, Budapest, Hungary. Mojtaba Mojtahedzadeh Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. & Pharmaceutical Research Center, Tehran University of Medical Sciences, Tehran, Iran. 2024 06 01 2024 06 02 Anticoagulation is the cornerstone of preventing thrombosis. Following the aging of society and the greater use of anticoagulant drugs, we see more serious complications in this group. The reduced occurrence of significant bleeding represents a notable benefit of direct oral anticoagulants (DOACs) in comparison to vitamin K antagonists. However, the unavailability of Andexanet alfa and Idarucizumab complicates the management of bleeding associated with DOACs. This case describes a 69-year-old man who presented with massive gastrointestinal bleeding, hemorrhagic shock, and loss of conciseness. He has been taking apixaban 2.5 mg twice a day, aspirin 80 mg once a day, and diltiazem 60 mg three times daily. Bleeding was controlled through transfusion of two units of fresh frozen plasma, five units of packed cell, four units of platelet, and tranexamic acid injection. Although hemorrhagic shock was successfully managed, he unfortunately passed away after three weeks of hospitalization following Ventilator-associated pneumonia and sepsis. In this case, we discuss the importance of the drug interaction of apixaban, diltiazem, and aspirin. https://aacc.tums.ac.ir/index.php/aacc/article/view/1016