Massive Intoxication with 70 Tablets of Apixaban: A Case Report

Abstract

Apixaban is a direct oral anticoagulation agent that exerts its effect through the direct inhibition of factor Xa. We treated a case of massive intoxication with 70 tablets of apixaban and have presented the clinical course of the associated anti-Xa activities. A 49-year-old woman was admitted to the emergency department approximately 1.5 h after impulsive self-intoxication with 175 mg of apixaban. She developed coagulopathy with prothrombin time-international normalized ratio (PT-INR) of 3.65, activated partial thromboplastin time of 56.5 s, and antithrombin activity (AT) of >150% (at 1.5 h post-ingestion). The patient’s initial and peak anti-Xa activity was 17.7 IU/mL, and its elimination displayed first-order kinetics with a half-life of 10.5 h. The patient’s anti-Xa activity was within the therapeutic dose range at 26 h post-ingestion, and she recovered without experiencing any bleeding complications. Her coagulopathy also returned to normal level at the same timing. This result suggests that PT-INR and AT can be used as substitute markers of overwhelmed anticoagulation following massive overdose of apixaban. A case of apixaban overdose with associated anti-Xa activities was presented. There was favorable resolution of anticoagulation without specific treatments.

Keywords

• antithrombin activity
• anti-xa activity
• apixaban
• intoxication
• prothrombin time-international normalized ratio