Rectal Bleeding and Hemostatic Disorders Induced by Dabigatran Etexilate in 2 Elderly Patients

OBJECTIVE: To report rectal bleeding associated with hemostatic disorders in 2 elderly patients treated with dabigatran etexilate. CASE SUMMARY: A 79-year-old woman (weight, 69 kg) was hospitalized in a gastroenterology unit for severe rectal bleeding. She had been treated for 2 months with dabigatran etexilate 110 mg twice daily for chronic atrial fibrillation. On admission, her creatinine clearance (CrCl) was 20.7 mL/min/1.73 m(2), prothrombin time (PT) less than 10% (reference range 70-130%), and international normalized ratio (INR) 14.5 (venous blood). Eleven days after admission, hematologic and renal function were normalized and rectal bleeding stopped. An 84-year-old man (weight, 71 kg) was admitted for rectal bleeding with acute renal failure and dehydration that began while he was treated with dabigatran etexilate 110 mg twice daily for atrial fibrillation. On admission, CrCl was 33.5 mL/min/1.73 m(2), PT 13%, and INR 7.53 (venous blood). Dabigatran etexilate was stopped on admission. At the end of the hospitalization, CrCl was 66.5 mL/min/1.73 m(2), PT 54%, and INR 1.53. In both cases, an objective causality assessment revealed that those adverse reactions were probably related to dabigatran etexilate. DISCUSSION: In these 2 cases of rectal bleeding during dabigatran etexilate therapy, coagulation monitoring showed elevated PT and INR; neither patient had been exposed to vitamin K antagonists. These cases indicate the importance of PT and INR monitoring when using dabigatran etexilate, mainly in patients with a high risk of overdose, such as elderly patients or those with renal function impairment. CONCLUSIONS: It is critical to identify and subsequently manage dabigatran etexilate toxicity because there is no specific antidote to reverse the drug's anticoagulant effects.