Rivaroxaban (Xarelto; Johnson & Johnson Services, Inc) is a direct oral anticoagulant (DOAC) that works by directly inhibiting the active site of factor Xa (FXa). Rivaroxaban is metabolized and cleared via the kidney and liver. The results of various studies have shown that patients with severe renal impairment should receive reduced dosages of rivaroxaban or another anticoagulant due to impaired clearance. Although it is not required, monitoring rivaroxaban is useful in some conditions; however, the assays required for such monitoring are not readily available. Herein, we present a case of a 68-year-old Caucasian male patient who was receiving rivaroxaban (20 mg/day) for atrial flutter and had mild renal impairment. The patient was found to have increased effect of rivaroxaban due to further impairment of renal clearance caused by several renally cleared medications. This case highlights the importance of closely examining the renal function of and medication list for a patient before starting DOACs such as rivaroxaban.
Keywords: DOAC; anticoagulation; bleeding; prolonged PT; renal impairment; rivaroxaban.
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