Cefepime's Neurotic Nexus: Complexities of Antibiotic-Induced Neurotoxicity

Introduction: Cefepime is a widely used fourth generation cephalosporin. It is primarily renally excreted, requiring dose adjustment in patients with deranged renal function. Cefepime-induced neurotoxicity, though rare, presents with neurological symptoms such as confusion, hallucinations and seizures. This case delves into the development of status epilepticus in a patient with renal insuffiency treated with cefepime. Case Description: 68-year-old female with pertinent right nephrectomy presented with generalized weakness, vomiting and diarrhea to the emergency department. Investigations revealed a urinary tract infection and acute kidney injury. Serum creatinine was 7.51 mg/dl (baseline 1.10 three months prior, and 3.68 one month before). Intravenous (IV) cefepime was started. Three days after starting IV cefepime, patient developed progressively worsening encephalopathy, leading to airway compromise and subsequent intubation. CT and MRI brain showed no acute abnormalities, while EEG revealed epileptiform discharges. Neurology was consulted and diagnosed status epilepticus and patient was started on anti-seizure medication. As dose of IV cefepime was not renally adjusted, there was concern about cefepime neurotoxicity. IV cefepime was stopped and patient was started on hemodialysis. Mental status improved and no further seizures were noted. Discussion: Cefepime has an elimination half life of 2.5 hours in patients with normal kidney function. This is increased with deranged kidney function. Risk factors for cefepime neurotoxicity include high dose, decreased renal clearance and increased penetration into the central nervous sytem as a result of dysfunction of the blood-brain barrier. Discontinuation of cefepime is the most important intervention. Sometimes dialysis is needed for rapid drug removal if symptoms persist. The low molecular weight and low protein binding facilitate its removal with dialysis. This case reinforces the importance of renally adjusting medications. A high index of suspicion is needed especially in patients with risk factors as the prognosis of cefepime neurotoxicity depends on early recognition and management. The diagnosis was cefepime neurotoxicity rather than uremia as patient's mental status improved after initial management and remained good despite worse renal parameters on her dyalisis days later on the stay.