Antibiotic-associated encephalopathy induced by cefmetazole in a hemodialysis patient: Case report

Antibiotic-associated encephalopathy (AAE) is a rare but significant neurological complication of β-lactam antibiotics, particularly in patients with renal impairment. While cefepime, ceftazidime, and ceftriaxone are well-documented causes, cefmetazole (CMZ) has not been widely recognized for neurotoxicity. We report an 82-year-old Japanese man with end-stage renal disease on chronic hemodialysis who developed altered mental status and myoclonus five days after starting intravenous CMZ for prostatic abscess. Electroencephalography (EEG) revealed triphasic waves consistent with non-convulsive status epilepticus. Neuroimaging and cerebrospinal fluid analysis showed no evidence of infection or stroke. Symptoms resolved within 48 hours of CMZ discontinuation. A Naranjo score of 5 supported a diagnosis of CMZ-induced AAE. This case underscores the potential neurotoxicity of CMZ and emphasizes the importance of early recognition of AAE in patients with renal dysfunction.