Felbamate overdose complicated by massive crystalluria and acute renal failure

Case Report: We report a 20-year-old woman who developed altered mental sta tus, massive crystalluria, and acute renal failure following an intentional overdose of felbamate and sodium valproate, Peak plasma concentrations of felbamate and sodium valproate were 200 mug/mL and 370 mug/mL, respectively . Macroscopic urinary crystals formed approximately 18 hours after ingestio n and mere identified bg gas chromatography as containing felbamate, Renal ultrasound revealed unilateral hydronephrosis. Following parenteral hydrati on, the crystalluria and acute renal failure resolved and the patient recov ered. The frequency and significance of crystalluria in felbamate intoxicat ion is unknown.