Cefepime (Maxipime) Coverage of Gram-Positive Cocci
Yes, cefepime provides good coverage against most Gram-positive cocci, including methicillin-susceptible Staphylococcus aureus (MSSA), Streptococcus pneumoniae, Streptococcus pyogenes, and viridans group streptococci, but it does NOT cover MRSA or enterococci. 1
Spectrum of Activity Against Gram-Positive Cocci
Cefepime demonstrates clinically significant activity against the following Gram-positive organisms:
Proven Clinical Efficacy
- Methicillin-susceptible Staphylococcus aureus (MSSA): Active both in vitro and in clinical infections 1
- Streptococcus pneumoniae: Including penicillin-resistant strains, with 97.4% susceptibility rates 2
- Streptococcus pyogenes (Group A Streptococcus): Excellent activity 1
- Viridans group streptococci: Excellent activity against most strains 1
Additional In Vitro Activity
- Methicillin-susceptible coagulase-negative staphylococci: Good activity, though clinical significance requires further validation 1
- Streptococcus agalactiae (Group B Streptococcus): At least 90% of isolates susceptible 1
Critical Limitations
Organisms NOT Covered
- MRSA (methicillin-resistant Staphylococcus aureus): Cefepime has poor activity and should never be used as monotherapy 3, 4
- Enterococci (Enterococcus faecalis): Resistant to cefepime 1, 3
- Methicillin-resistant coagulase-negative staphylococci: Resistant 1
Comparative Potency
Cefepime is approximately 4-fold more active than ceftazidime against MSSA (MIC90 = 4 μg/mL vs 16 μg/mL), achieving 100% susceptibility compared to ceftazidime's 86.4% 2. Against streptococci, the activity hierarchy is: vancomycin > ceftriaxone > cefepime > penicillin > erythromycin > ceftazidime, with cefepime being approximately 8 times more potent than ceftazidime against S. pneumoniae 5.
Clinical Applications for Gram-Positive Coverage
When Cefepime Alone is Appropriate
- Mild to moderate infections with confirmed MSSA or streptococcal species where MRSA is not suspected 6
- Febrile neutropenia: Cefepime monotherapy provides adequate coverage for streptococcal infections, including viridans streptococci 6, 5
When Combination Therapy is Required
- Severe diabetic foot infections: Vancomycin plus cefepime when MRSA, Enterobacteriaceae, Pseudomonas, and anaerobes may be present 6
- Empiric therapy for severe infections or septic shock: Add vancomycin to cefepime when MRSA coverage is needed based on local epidemiology 7
- Anaerobic coverage needed: Add metronidazole to cefepime for intra-abdominal infections 8, 5
Common Pitfalls to Avoid
- Never use cefepime monotherapy when MRSA is suspected or confirmed - this is the most critical error, as cefepime has no meaningful activity against methicillin-resistant organisms 1, 3
- Do not assume enterococcal coverage - if enterococcal infection is suspected (particularly in intra-abdominal or urinary sources), add ampicillin or vancomycin 1
- Failing to consider local resistance patterns - while cefepime maintains excellent activity against MSSA (100% susceptibility in surveillance data), institutional antibiograms should guide empiric choices 2
- Overlooking the need for anaerobic coverage - cefepime lacks anti-anaerobic activity and requires metronidazole for polymicrobial infections 5, 9
Surveillance Data
Large-scale North American surveillance (1998-2003) demonstrated that cefepime maintained stable and excellent activity against oxacillin-susceptible S. aureus (100% susceptible) and S. pneumoniae (97.4% susceptible) over the 6-year period, with MIC90 values of 4 μg/mL and 1 μg/mL respectively 2. This sustained activity supports its continued use for susceptible Gram-positive infections 10, 2.