From the FDA Drug Label
Cefepime Injection is indicated for uncomplicated skin and skin structure infections caused by Staphylococcus aureus (methicillin-susceptible isolates only) or Streptococcus pyogenes. Cefepime has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections: Gram-positive bacteria Staphylococcus aureus (methicillin-susceptible isolates only)
- Cefepime is effective against methicillin-susceptible Staphylococcus aureus (Staph aureus), but its effectiveness against methicillin-resistant Staphylococcus aureus is not established 1.
- Key points:
- Cefepime covers Staph aureus, but only methicillin-susceptible isolates.
- Methicillin-resistant Staphylococcus aureus is not covered by cefepime.
From the Research
Cefepime is generally effective against methicillin-sensitive Staphylococcus aureus (MSSA), but its effectiveness against methicillin-resistant Staphylococcus aureus (MRSA) is limited. The typical adult dosage for serious S. aureus infections is 1-2 grams administered intravenously every 8-12 hours, with adjustments needed for patients with renal impairment 2. However, for suspected or confirmed MRSA infections, alternative agents such as vancomycin, linezolid, or daptomycin should be considered instead. Cefepime works by binding to penicillin-binding proteins in the bacterial cell wall, disrupting cell wall synthesis and causing bacterial cell death. As a fourth-generation cephalosporin, cefepime has enhanced stability against certain beta-lactamases and good penetration through the outer membrane of gram-negative bacteria, but its activity against S. aureus is similar to earlier generation cephalosporins. Some key points to consider when using cefepime against Staphylococcus aureus include:
- Cefepime has been shown to be effective against MSSA, with a MIC90 of 1.5 micrograms/mL 2
- Cefepime is not effective against MRSA, and alternative agents should be considered for suspected or confirmed MRSA infections
- The combination of cefepime with other antimicrobials, such as vancomycin or aminoglycosides, may enhance its effectiveness against MRSA 3, 4, 5
- Cefepime should be used with caution in patients with renal impairment, and dosage adjustments may be necessary. It's worth noting that the most recent study 5 suggests that concomitant empiric cefepime may improve MRSA BSI clearance when used in combination with vancomycin, which may be useful in certain clinical scenarios.