Fatal dabigatran-associated bleeding

We read with great interest the case presented by Schaeffer and Conway1 describing a fatal outcome with the use of dabigatran and would like to address several points about the patient’s medical management. We find it peculiar that the patient received the medications she did in the first place, given her advanced age, comorbidities, and high risk of major bleeding. We are surprised that there did not seem to be a pharmacist intervention at any point in the care of the patient. After the patient developed paroxysmal atrial fibrillation, she was prescribed warfarin sodium 10 mg daily for three days while in the hospital. Harrison et al.2 found that patients given a 10-mg loading dose of warfarin sodium had more above-target International Normalized Ratio (INR) values than patients receiving 5 mg. On the third day, the INR for the current patient was 1.3, which prompted the physician to prescribe dabigatran 150 mg twice daily. However, given warfarin’s slow onset, responding to an INR of 1.3 was likely premature. Warfarin exhibits a long half-life of approximately 20–60 hours,3 and it is likely that much of the INR of 8.3 arising eight days later was due to warfarin as well as dabigatran. Hylek et al.4 found that INR decay back to baseline was significantly delayed in patients of advanced age, especially those age 80 years or older (the current patient was 78 years old).