What antibiotics have antistaphylococcal coverage for adults with staphylococcal pneumonia?

Antibiotics for Staphylococcal Pneumonia in Adults

For adults with staphylococcal pneumonia, first-line antistaphylococcal antibiotics include vancomycin for MRSA infections and oxacillin, nafcillin, or cefazolin for confirmed MSSA infections. 1, 2

Empiric Therapy for Suspected Staphylococcal Pneumonia

For MRSA Coverage:

• Vancomycin 15 mg/kg IV q8-12h (consider loading dose of 25-30 mg/kg for severe illness) 1, 2
• Linezolid 600 mg IV q12h (alternative option, particularly for patients with vancomycin treatment failure, isolates with vancomycin MICs >2 μg/mL, or vancomycin-induced nephrotoxicity) 1, 3

For MSSA Coverage:

• Oxacillin, nafcillin, or cefazolin are preferred agents for confirmed MSSA infections 1, 4
• Piperacillin-tazobactam, cefepime, levofloxacin, imipenem, or meropenem can provide coverage for suspected MSSA as part of empiric therapy 1

Risk Stratification for Empiric Therapy

Risk Factors for MRSA:

• Prior intravenous antibiotic use within 90 days 1, 2
• Treatment in a unit where MRSA prevalence among S. aureus isolates is >20% or unknown 1, 2
• Prior detection of MRSA by culture or screening 1, 2

Risk Factors for Mortality:

• Need for ventilatory support due to pneumonia 1, 2
• Septic shock 1, 2

Definitive Therapy Based on Culture Results

For Confirmed MRSA:

• Continue vancomycin or linezolid 1, 5
• Telavancin may be considered as an alternative (although availability may be limited) 5, 3

For Confirmed MSSA:

• Narrow to oxacillin, nafcillin, or cefazolin (preferred over broader agents) 1, 2
• First-generation cephalosporins (cefazolin) are appropriate for less serious MSSA infections or in patients with non-immediate penicillin hypersensitivity 4

Special Considerations

For Severe Penicillin Allergy:

• For non-immediate reactions: Cefazolin can be used for MSSA 4
• For immediate reactions (urticaria, angioedema, bronchospasm, anaphylaxis): Avoid cephalosporins 4
• Consider vancomycin for both MRSA and MSSA coverage in patients with severe immediate penicillin allergy 4
• Aztreonam may be used for gram-negative coverage but must be combined with MSSA coverage if aztreonam is used instead of a β-lactam 1

For Combination Therapy:

• For high-risk patients with suspected staphylococcal pneumonia, consider combination therapy with two antipseudomonal agents from different classes if gram-negative coverage is also needed 1, 2
• For multi-resistant MRSA (mrMRSA), combination therapy (e.g., rifampicin and fusidic acid) may be necessary as resistance develops rapidly with monotherapy 4

Common Pitfalls to Avoid

• Using inappropriate monotherapy in high-risk patients who require combination therapy 2
• Using unnecessarily broad-spectrum antibiotics in low-risk patients, contributing to antimicrobial resistance 2
• Using aminoglycosides as the sole antipseudomonal agent in patients with HAP 1
• Failing to adjust therapy based on culture results and clinical response 2
• Using daptomycin for staphylococcal pneumonia (higher death rates and serious cardiorespiratory adverse events have been reported in pneumonia patients) 6

Newer Agents with Activity Against Staphylococcus aureus

• Ceftaroline has activity against MRSA, including in skin and skin structure infections 7, 5
• Tigecycline, quinupristin/dalfopristin, and other newer agents may be considered for specific situations but have limited evidence for staphylococcal pneumonia 5, 3, 8