Background: Drug-induced nephrolithiasis is a rare finding, especially with beta-lactamins. We report a case of acute renal failure due to amoxicillin crystallization.
Case report: A 48 year-old woman was admitted because of pneumococcal meningitis. After 4 days on high-dose amoxicillin (320 mg/kg/day), she developed acute oliguric renal failure and amoxicillin crystallization was documented by infrared spectrometry. The outcome was favorable after amoxicillin dosage tapering, together with one single hemodialysis session and further hydratation.
Discussion: Amoxicillin is mainly excreted in the urine in its unchanged form. The risk of crystalluria is increased by low urinary pH, low urine output and high-dose of the drug. Such a crystalluria should be accurately identified by infrared spectrometry.