To the Editor: I read with interest the review of dabigatran (Pradaxa) by Drs. Wartak and Bartholomew , which provides an excellent overview of this new oral anticoagulant. 1
This article does not mention clearly two key points about the guidelines for using dabigatran, which are different in the United States than in the other 75 countries where it has been approved. 1 First, the RE-LY trial 2,3 excluded patients with a creatinine clearance rate less than 30 mL/min/1.73 m 2, a common situation in the elderly. Second, in contrast to other countries, the US Food and Drug Administration (FDA) approved dabigatran for patients with a creatinine clearance rate of 15 to 30 mL/min/1.73 m 2, although at a lower dose. 3 No dose adjustment is suggested in patients with less severe (mild or moderate) renal impairment. 3 This may lead to potential misuse and problems. In fact, lethal side effects have been reported in France by Legrand et al. 4 Furthermore, a report is in press on dabigatran-associated acute renal failure, 5 and recently the German publication Die Zeit reported 50 deaths from bleeding in patients with atrial fibrillation treated with dabigatran. 6
Therefore, despite suggestions that dabigatran does not require monitoring of its effects during treatment, 1,3 renal, hematologic, and hepatic variables should be monitored before and after initiation of dabigatran 5 until more experience is gained with this new drug, and especially in the elderly and those with chronic kidney disease that is stage 4 (estimated glomerular filtration rate 15–29 mL/min/1.73 m 2) or stage 5 (< 15 mL/min/1.73 m 2).