Amoxicillin-Induced Hemolytic Uremic Syndrome and Kidney Injury: A Case Report

Amoxicillin (AMX) is a commonly used antibiotic for treating infections and as a prophylactic antimicrobial agent, appreciated for its efficacy and favorable pharmacokinetics. Drug-induced acute kidney injury (AKI) significantly increases morbidity and mortality. Hemolytic uremic syndrome (HUS) is classified under thrombotic microangiopathies (TMAs), which are characterized by hemolysis, low platelet counts, thrombus formation in small vessels, and end-organ damage. While AMX-induced HUS has not been previously reported, AMX can cause AKI through mechanisms such as acute interstitial nephritis and AMX-induced crystal nephropathy (AICN), with AICN being more common. We present the case of a 56-year-old woman who developed AMX-induced HUS and AKI following AMX administration for a tooth infection. A kidney biopsy revealed distinctive glomerular damage, consistent with acute tubular injury and focal segmental glomerulonephritis. The diagnosis of drug-induced kidney injury with concurrent TMA was confirmed. AMX was discontinued, and the patient received plasmapheresis and hemodialysis. Typically, renal impairment is reversible once the offending agent is withdrawn. Physicians should be aware of the potential for AMX-induced HUS. Comprehensive medical history, physical examination, and prompt therapeutic intervention are crucial for effective treatment and improved patient outcomes.