Development of cefepime-induced encephalopathy in a patient with depression and rectal cancer: A case report

Cefepime, a fourth-generation cephalosporin, has neurotoxic side effects such as encephalopathy. Baseline conditions, including blood-brain barrier (BBB) impairment and renal dysfunction, are known to associate with elevated central nervous concentration of cefepime. Although BBB dysfunction occurs with depression or cancer, currently, neither is regarded as a risk factor for cefepime-induced encephalopathy.

A 79-year-old woman with a history of depression and rectal cancer was hospitalized for a bacterial liver abscess. Brain metastasis and other causes for delirium were excluded, and no renal dysfunction was observed. However, 11 days after cefepime and metronidazole administration, the patient suddenly developed confusion, disorientation, and myoclonus, with no apparent changes on brain magnetic resonance imaging. Electroencephalography revealed a consistent tri-phasic wave pattern. Clinical symptoms were well consistent with cefepime-induced encephalopathy; hence, cefepime and metronidazole were discontinued, followed by rapid physical and mental recovery, with no aftereffects.

In terms of BBB dysfunction, depression and cancer might be possible occult risk factors for cefepime-induced encephalopathy. Doctors need to pay attention to encephalopathy risk when administering cefepime in patients with depression or cancer because the psychiatric symptoms of encephalopathy, depression, and delirium from other causes are often confusing, leading to misdiagnosis and a poor prognosis.