Warfarin related nephropathy: a case report and review of the literature

BACKGROUND: Warfarin related nephropathy is one of the potential complications of warfarin therapy. Despite the well described histological entity, the clinical course and approach to warfarin related nephropathy in patients requiring life-long anticoagulation is however not well described in the literature. CASE PRESENTATION: We report the clinical course of a 56 years old Chinese lady who presented with over anti-coagulation and acute kidney injury while on warfarin therapy for permanent atrial fibrillation and mechanical valve replacement. Renal biopsy was performed as the acute kidney injury was persistent despite normalization of the International Normalized Ratio and the diagnosis of warfarin related nephropathy was made. Temporary interruption of anti-coagulation, in combination with oral N-acetylcysteine resulted in subsequent stabilization of renal function. CONCLUSION: The diagnosis of warfarin induced nephropathy should be considered in patients presenting with unexplained acute kidney injury and over anti-coagulation. Awareness of this clinical entity is important for clinician managing anti-coagulation therapy and renal function should be monitored regularly in patients who are on warfarin therapy.