Can cefepime cause confusion in patients with impaired renal function?

Cefepime and Confusion in Patients with Impaired Renal Function

Yes, cefepime can definitely cause confusion and other neurological symptoms in patients with impaired renal function, and this neurotoxicity can occur even when doses are adjusted for renal function. 1, 2

Mechanism and Risk Factors

• Cefepime has a high pro-convulsive activity (160 relative to penicillin G at 100), making it one of the most neurotoxic beta-lactam antibiotics 1
• Renal impairment is the primary risk factor for cefepime-induced neurotoxicity due to drug accumulation 1, 2
• Neurotoxicity can occur even when dosing is appropriately adjusted for renal function (26% of cases) 1, 3

Clinical Manifestations

• Neurological symptoms typically appear 1-10 days after starting treatment (average 4.75 days) 4
• Manifestations include:
  • Acute confusional state/encephalopathy 1, 5
  • Decreased consciousness 4
  • Global aphasia 4
  • Myoclonus and movement disorders 2, 4
  • Seizures and non-convulsive status epilepticus 2, 3
  • Coma 4

Diagnostic Considerations

• EEG findings typically show diffuse slow-wave activity (delta) and triphasic sharp waves 4, 5
• Cefepime trough concentrations above 22 mg/L (with discontinuous infusions) or steady-state concentrations above 35 mg/L (with continuous infusion) are associated with neurotoxicity in 50% of patients 1
• Symptoms may be misattributed to other causes of encephalopathy, especially in critically ill patients 6

Prevention and Management

• For patients with renal impairment:

  • Dose adjustment is essential but may not be sufficient to prevent neurotoxicity 2, 3
  • Consider therapeutic drug monitoring when available 6
  • Be vigilant for neurological symptoms, especially in patients with additional risk factors such as history of stroke or seizures 3

• If neurotoxicity is suspected:

  • Immediately discontinue cefepime 1, 3
  • Consider hemodialysis in severe cases, which can accelerate drug clearance 7
  • Symptoms typically resolve within 24-48 hours after drug discontinuation 5

Special Considerations

• Overdose symptoms include encephalopathy, confusion, hallucinations, stupor, coma, myoclonus, seizures, and neuromuscular excitability 2
• In patients with severe renal impairment, hemodialysis (not peritoneal dialysis) is recommended to aid in cefepime removal 2
• The FDA label specifically warns about neurotoxicity in patients with renal impairment who receive unadjusted doses 2

Alternative Approaches

• Consider alternative antibiotics with lower neurotoxic potential in patients with renal impairment 6
• If cefepime must be used in renal impairment, implement close clinical and laboratory monitoring 6

Cefepime-induced neurotoxicity is potentially life-threatening but completely reversible if recognized promptly. Clinicians should maintain a high index of suspicion for this adverse effect when patients with renal impairment develop new neurological symptoms while receiving cefepime, even when appropriate dose adjustments have been made. 4, 3