What is the cefepime dose for a 29-year-old male with moderate renal impairment (GFR of 48 mL/min)?

Cefepime Dosing for a 29-Year-Old Male with GFR of 48 mL/min

For a 29-year-old male with moderate renal impairment (GFR of 48 mL/min), the appropriate cefepime dose is 2 grams every 24 hours (for severe infections) or 1 gram every 24 hours (for mild to moderate infections). 1

Dosing Rationale

The FDA-approved drug labeling for cefepime provides specific guidance for patients with renal impairment:

• For patients with GFR between 30-60 mL/min:
  • 500 mg every 24 hours (for mild infections)
  • 1 g every 24 hours (for moderate infections)
  • 2 g every 24 hours (for severe infections like pneumonia or febrile neutropenia)

Factors Influencing Dose Selection

1. Severity of infection:

   • Mild to moderate uncomplicated UTIs: 1 g every 24 hours
   • Severe infections (pneumonia, complicated UTIs, skin infections): 2 g every 24 hours
   • Febrile neutropenia or Pseudomonas infections: 2 g every 24 hours

2. Renal function:

   • With GFR of 48 mL/min, the patient falls into the 30-60 mL/min category requiring dose adjustment
   • This moderate renal impairment necessitates reducing frequency from twice or three times daily to once daily

Clinical Considerations

Pharmacokinetics in Renal Impairment

Cefepime is primarily eliminated by the kidneys, with over 80% recovered unchanged in urine in patients with normal renal function 2. With reduced renal function, drug clearance decreases proportionally to creatinine clearance, necessitating dose adjustment to prevent accumulation.

Monitoring Recommendations

1. Neurological status: Monitor for signs of neurotoxicity, which can manifest as:

   • Confusion
   • Disorientation
   • Myoclonus
   • Seizures

2. Renal function: Regular monitoring of renal function is essential as further deterioration would require additional dose adjustments.

Potential Complications

Cefepime-induced encephalopathy is a serious concern in patients with renal impairment. Research has shown that patients with GFR <60 mL/min are at increased risk for this complication 3. The risk increases with lower GFR values, with studies showing a mean GFR of 17.2 mL/min in patients who developed encephalopathy.

Common Pitfalls to Avoid

1. Overdosing: Using standard doses in patients with renal impairment can lead to drug accumulation and neurotoxicity.

2. Underdosing: Excessive dose reduction may lead to treatment failure and development of resistance.

3. Failure to reassess: Renal function may change during treatment, especially in critically ill patients, requiring dose adjustments.

4. Ignoring drug interactions: Concomitant nephrotoxic medications may further impair renal function and affect cefepime clearance.

By following these dosing guidelines and monitoring recommendations, you can optimize therapeutic efficacy while minimizing the risk of adverse effects in this patient with moderate renal impairment.