Cefepime Dosing in Moderate Kidney Disease (GFR 49)
For a patient with moderate kidney disease and GFR of 49 mL/min, the recommended dose of cefepime is 2 grams every 24 hours.
Dosing Rationale
Cefepime is primarily eliminated by the kidneys, and dosage adjustment is necessary when renal function is impaired. According to the FDA drug label 1, dose adjustment is required for patients with creatinine clearance less than or equal to 60 mL/min to compensate for the slower rate of renal elimination.
Dosing Algorithm Based on GFR:
- GFR >60 mL/min: Standard dosing (1-2g every 12 hours)
- GFR 30-60 mL/min: 2g every 24 hours
- GFR 10-29 mL/min: 1g every 24 hours
- GFR <10 mL/min: 500mg every 24 hours
- Hemodialysis patients: 1g every 24 hours, with supplemental dose after dialysis
Risk of Cefepime Neurotoxicity
Cefepime neurotoxicity is a significant concern in patients with renal dysfunction. Studies have shown that:
- Patients with renal impairment are at higher risk of developing cefepime-induced neurotoxicity 2
- Neurotoxicity can manifest as altered mental status, myoclonus, seizures, and even non-convulsive status epilepticus 3
- The risk increases when dosing is not appropriately adjusted for renal function 3
A 2013 study found that 15% of ICU patients receiving cefepime developed neurotoxicity, with chronic kidney disease being a significant risk factor (present in 66.7% of those with neurotoxicity vs. 35.3% without) 3.
Important Monitoring Considerations
When administering cefepime to a patient with GFR 49 mL/min:
- Monitor neurological status closely for signs of neurotoxicity
- Watch for symptoms including:
- Altered mental status
- Myoclonus
- Disorientation
- Seizure activity
- Consider EEG if neurological symptoms develop
- Reassess renal function regularly during therapy
Special Considerations
- Cefepime is known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function 1
- Even with appropriate dose adjustment, neurotoxicity can still occur 3
- If signs of neurotoxicity develop, consider discontinuing cefepime and switching to an alternative antibiotic
Conclusion
For a patient with moderate kidney disease and GFR of 49 mL/min, cefepime should be dosed at 2 grams every 24 hours with close monitoring for signs of neurotoxicity. This dosing recommendation balances the need for effective antimicrobial therapy while minimizing the risk of adverse effects related to renal dysfunction.