What is the recommended dose of Cefepime for an elderly male with pneumonia (PNA) and normal renal function?

Cefepime Dosing for Pneumonia in Elderly Males

For an elderly male with pneumonia and normal renal function (creatinine clearance ≥60 mL/min), administer cefepime 2 g IV every 8 hours. 1

Standard Dosing Regimen

The recommended dose is cefepime 2 g IV every 8 hours for hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), or severe community-acquired pneumonia requiring ICU admission. 1 This dosing applies regardless of age when renal function is preserved, as age alone does not require dose adjustment. 2

• Alternative dosing of 1-2 g every 8-12 hours may be considered for less severe infections, but the 2 g every 8 hours regimen provides optimal coverage for multidrug-resistant organisms commonly encountered in pneumonia. 1
• The higher dose (2 g every 8 hours) is particularly important when Pseudomonas aeruginosa or other resistant Gram-negative pathogens are suspected. 1

Critical Consideration: Renal Function Assessment

Elderly patients require mandatory creatinine clearance calculation before dosing, as renal function declines with age even when serum creatinine appears normal. 2

• Use the Cockcroft-Gault equation to calculate creatinine clearance, as this is the standard referenced in dosing guidelines. 2, 3
• If creatinine clearance is 30-60 mL/min: reduce to 2 g IV every 12 hours or 1 g IV every 8 hours. 2
• If creatinine clearance is 11-29 mL/min: reduce to 2 g IV every 24 hours or 1 g IV every 12 hours. 2
• If creatinine clearance is ≤10 mL/min: reduce to 1 g IV every 24 hours. 2

Infusion Duration and Administration

• Standard infusion time is 30 minutes for the 2 g dose. 4
• Extended infusion over 3-4 hours may optimize pharmacodynamic targets (maintaining concentrations above MIC for ≥50% of the dosing interval) and should be considered for critically ill patients or when treating organisms with MIC values of 4-8 mg/L. 3, 5

Safety Monitoring in Elderly Patients

Monitor for neurotoxicity, particularly in patients with any degree of renal impairment, as elderly patients are at higher risk even with dose adjustment. 5

• Neurotoxic symptoms include confusion, encephalopathy, myoclonus, seizures, and non-convulsive status epilepticus. 5
• Maintain trough concentrations <20 mg/L to minimize neurotoxicity risk. 3
• Consider therapeutic drug monitoring if creatinine clearance is <50 mL/min or if neurological symptoms develop. 3, 5

Clinical Context for Dosing Selection

The 2 g every 8 hours regimen is specifically recommended for:

• Late-onset HAP/VAP (≥5 days of hospitalization). 1
• Risk factors for multidrug-resistant organisms (prior antibiotics, structural lung disease, immunosuppression). 1
• Severe pneumonia requiring ICU admission. 1
• Empiric coverage when Pseudomonas aeruginosa is a concern. 1

Cefepime should typically be combined with coverage for atypical pathogens (macrolide or respiratory fluoroquinolone) and MRSA (vancomycin or linezolid) when used empirically for severe pneumonia, though this depends on local epidemiology and patient risk factors. 1