Amoxicillin crystalluria and amoxicillin-induced crystal nephropathy: a narrative review

Amoxicillin crystalluria (AC) refers to the precipitation of amoxicillin in the urine as amoxicillin trihydrate crystals. Amoxicillin-induced crystal nephropathy (AICN) refers to the obstruction of kidney tubules by amoxicillin trihydrate crystals, resulting in acute kidney injury. Usually considered rare and not serious, AC and AICN would be more frequent in patients receiving high-dose i.v. amoxicillin (≥150 mg/kg per day) than previously reported. AC prevalence ranges from 24% to 41%. AICN prevalence remains unclear.