Ertapenem-Induced Delirium

Neurotoxicity is an unusual iatrogenic effect associated with carbapenems, typically manifested as seizures or hyperactive delirium. We present an 89-year-old female patient with a medical history of hypertension and chronic kidney disease who was admitted for acute tracheobronchitis and anemia related to diverticular disease. As a complication, she developed acute cystitis caused by extended spectrum ß-lactamases producing Klebsiella pneumoniae, so intravenous ertapenem was started. On the second day of antibiotic therapy, the patient manifested visual hallucinations followed by an inattentive and lethargic state suggestive of a hypoactive delirium. An ertapenem-induced neurotoxicity was suspected. Upon substitution by meropenem, the patient improved, and symptom reversal occurred after 72 hours. We present a review of ertapenem-induced hallucinations and address pharmacokinetics aspects namely renal dysfunction and hypoalbuminemia that could potentiate encephalopathy. Although rare, clinicians should be aware of non-seizure ertapenem related neurotoxicity. Ready recognition can lead to rapid improvement and prevent dire outcomes.