Risk Factors for Bleeding Events with Enoxaparin, Dabigatran and Fondaparinux in Hospitalized Patients with Varying Levels of Renal Impairment

Background: Anticoagulants with renal elimination may accumulate in patients with renal impairment and potentially increase the risk of bleeding. Limited data are available to elucidate the potential bleeding risk present in patients with moderate renal impairment defined as creatinine clearance of 30-50 mL/min. Objective: To evaluate potential risk factors for bleeding over various renal function ranges in patients on enoxaparin, fondaparinux, or dabigatran. Methods: Retrospective chart review from 2010 until 2011 identified patients who incurred a bleeding episode on therapeutic dosed enoxaparin, dabigatran, or fondaparinux stratified according to renal function and presence of pre-defined potential risk factors for bleeding. Bleeding episodes identified using UHC Safety Intelligence, a selfreporting database used to identify safety improvement opportunities. Results: A total of 27 (2.16%) bleeding episodes were identified, 20 occurring during enoxaparin pharmacotherapy and 7 during treatment with dabigatran. There were no fondaparinux bleeds identified. Patients with normal renal function, moderate renal impairment and severe renal impairment incurred 9, 12 and 6 bleeds, respectively. Conclusion: A similar number of patients incurred bleeding episodes on enoxaparin in the normal renal function group and moderate renal impairment group. Patients experiencing bleeding episodes in the enoxaparin group with moderate renal impairment were of advanced age and female. Enoxaparin bleeding episodes were noted in patients with hypertension in all renal function ranges. Patients who bled on dabigatran had some degree of renal impairment and were of advanced age. Concomitant p-glycoprotein inhibitor use was observed in patients with bleeding episodes on dabigatran in patients with renal impairment.