A Case of Ertapenem-Induced Neurotoxicity in an Elderly Patient With Reduced Renal Function

Ertapenem-induced neurotoxicity is a rare, often underreported side effect, primarily seen in elderly patients with impaired renal function. We report the case of an 87-year-old woman with a history of chronic kidney disease (CKD) and bilateral hydronephrosis, who presented with acute neurological symptoms, including left-sided weakness and slurred speech. Prior to this presentation, she had been treated for a left-sided nephrostomy site infection and left-sided perinephric collection with intravenous ertapenem at an ambulatory emergency care (AEC) center. An initial computed tomography (CT) scan of the brain showed no acute changes, but we treated her for a possible stroke while awaiting a magnetic resonance imaging (MRI) scan of the brain and continued intravenous ertapenem for the associated urological infection. However, the patient's condition continued to deteriorate, with the onset of further neurological symptoms, such as left-sided sensory deficits and constant myoclonic movements. An MRI scan of the brain showed no significant changes. The patient was diagnosed with ertapenem-induced neurotoxicity. We discontinued the antibiotic and switched to meropenem. Her neurological symptoms gradually improved and subsided within a week of stopping ertapenem. This case highlights the importance of clinical suspicion of ertapenem-induced neurotoxicity in elderly and frail patients with reduced renal function who present with unexplained neurological symptoms. Prompt recognition of the condition facilitates accurate diagnosis and management. Treatment is simple and involves discontinuing the offending drug, leading to favorable outcomes.