Amoxicillin Crystalluria: A Rare Side-Effect of a Commonly Prescribed Antibiotic

Although crystalluria is a frequent finding in the routine examination of urine, amoxicillin crystalluria is a rare event whose incidence remains unknown. Crystalluria caused by amoxicillin is very uncommon and may be asymptomatic or have severe renal implications. The authors describe the case of an 87-year-old female patient who presented with massive amoxicillin crystalluria due to poor hydration, low urinary pH and high intravenous amoxicillin dosage. LEARNING POINTS: Amoxicillin crystalluria is a rare event. It can range from a transient asymptomatic crystalluria without renal damage to major haematuria or acute renal failure. We should be aware of this complication because high intravenous doses of amoxicillin are frequently prescribed and measures can be adopted to prevent this complication.