Adverse Event: Warfarin-related nephropathy., Drug Implicated: Warfarin., The Patient: A 31-year-old female, managed with warfarin for rheumatic heart disease with atrial fibrillation., Evidence That Links the Drug to the Event: There were no alternative causes of nephropathy that could have caused the adverse event in this patient., Management: Shifting the drug from warfarin to acenocoumarol., Mechanism: Difference in renal elimination between warfarin and acenocoumarol., Implication for Therapy: Clinicians should be aware of this rare adverse effect of warfarin, and acenocoumarol can be considered as an alternative therapy for this condition., Hypotheses to Be Tested: Further prospectively designed studies are needed to consider acenocoumarol as an alternative therapy in warfarin-related nephropathy., (© 2018 The British Pharmacological Society.)