A Rare Case of Late-Onset Ertapenem-Induced Encephalopathy

Abstract

Encephalopathy is a rare side effect associated with carbapenem antibiotics, typically presenting within one week of initiating treatment. It is almost exclusively seen in patients with poor renal function. We present a case of a middle-aged male with a history of cerebral vascular accident and normal renal function admitted for agitation, delirium, and insomnia more than two weeks after starting ertapenem to treat osteomyelitis. He was empirically treated for meningitis on admission, and ertapenem was discontinued. After an extensive negative workup for infectious and neurological etiologies of encephalopathy, a presumptive diagnosis of ertapenem-induced encephalopathy was made. The patient returned to his baseline mental status five days after discontinuing ertapenem. The nature of his neurological symptoms and timely resolution after stopping ertapenem is consistent with ertapenem-induced encephalopathy and represents a notably delayed symptom onset compared to previously described cases.

A Case of Ertapenem-Induced Delirium

“…Review of the literature reveals a number of case reports and case series wherein patients experienced acute delirium or encephalopathy secondary to ertapenem treatment [ 4 - 11 ]. Reported symptoms included hallucinations [ 4 , 5 , 7 , 9 , 11 ], suicidal ideation [ 11 ], delirium [ 4 - 11 ], agitation [ 4 , 7 , 10 ], seizures [ 8 ], encephalopathy (neurotoxicity) [ 4 - 11 ], miosis [ 6 ], dysphasia [ 5 , 6 ], and altered mental status [ 4 - 11 ]. Common risk factors in these reports were older patients [ 6 - 9 , 11 ], prolonged treatment for more than seven days [ 4 - 7 , 9 - 11 ], and renal impairment [ 4 - 6 , 8 , 9 ].…”

“…Another common factor in these reports was a delayed recognition of the link between delirium and ertapenem treatment [ 7 , 8 , 10 ]. This highlights the importance of pharmacovigilance in clinical practice, especially when dealing with multi-morbid patients.…”