Safety and Efficacy of Apixaban in Severe Renal Impairment

Despite emergence of new anticoagulants over the last few years, patients with advanced chronic kidney disease still have limited options and are usually managed with warfarin after venous thromboembolism or diagnosis of atrial fibrillation. The use of all direct oral anticoagulants is not recommended in patients with creatinine clearance below 15 mL/min. Apixaban has the lowest fraction of renal excretion (27%) and is sometimes used in patients with CKD V (GFR \< 15 mL/min/BSA) and end stage renal disease (ESRD). Until recently, data on apixaban use in this population were limited to pharmacodynamics as patients with severe renal impairment were excluded from clinical trials. In a 2016 study, it was found that ESRD resulted in 36% increase in apixaban AUC but no increase in Cmax, and that hemodialysis had a limited impact on apixaban clearance.1 There are now data available on inpatient use of apixaban vs.coumadin in patients with creatinine clearance below 25 ml/min.2 There was no significant difference in bleeding events between the two groups but the study period was limited to a hospital admission and may not reflect bleeding risk of long-term anticoagulation. Use of warfarin in patients on hemodialysis entails several disadvantages in this population. The need for INR monitoring adds clinic visits for patients that already spend a great portion of their time in healthcare facilities. Numerous drug interactions, involving warfarin, complicate management of ESRD patients that are often on many medications. The reduced risk of intracranial bleeding on apixaban, compared to warfarin, in the ARISTOTLE study, is an important consideration in patients that may already be at increased risk due other factors such as uremia and concurrent antiplatelet agents.