What is the recommended treatment for community-acquired pneumonia (CAP)?

Treatment of Community-Acquired Pneumonia (CAP)

The recommended first-line treatment for community-acquired pneumonia is a beta-lactam (such as amoxicillin, ceftriaxone, or cefotaxime) combined with a macrolide (preferably azithromycin) for hospitalized patients, or monotherapy with a respiratory fluoroquinolone (such as levofloxacin) for patients with beta-lactam allergies. 1

Pathogen-Specific Considerations

The choice of antibiotics should be guided by the most likely pathogens:

• Streptococcus pneumoniae: The predominant bacterial pathogen in CAP

  • First-line: Beta-lactams (amoxicillin, cefotaxime, ceftriaxone) 1
  • Note: Cefixime should NOT be used due to poor activity against S. pneumoniae, especially penicillin-resistant strains 1

• Atypical pathogens (Mycoplasma pneumoniae, Legionella spp., Chlamydophila pneumoniae):

  • First-line: Macrolides (azithromycin preferred), tetracyclines, or respiratory fluoroquinolones 1

Treatment Algorithms by Patient Setting

Outpatient Treatment

• Healthy patients without comorbidities:

  • Amoxicillin OR
  • Doxycycline OR
  • Macrolide (azithromycin) 1

• Patients with comorbidities or recent antibiotic use:

  • Combination of beta-lactam + macrolide OR
  • Respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily for 5 days) 2, 3

Hospitalized Patients (Non-ICU)

• Standard therapy:
  • Beta-lactam (ceftriaxone, cefotaxime, ampicillin-sulbactam) + macrolide (azithromycin) 1, 4
  • Alternative: Respiratory fluoroquinolone monotherapy 1

Severe CAP/ICU Patients

• Standard therapy:

  • Beta-lactam + macrolide OR
  • Beta-lactam + respiratory fluoroquinolone 1

• If Pseudomonas suspected:

  • Antipseudomonal beta-lactam (piperacillin-tazobactam, cefepime, imipenem, meropenem) + either ciprofloxacin/levofloxacin or aminoglycoside + azithromycin 1

• If CA-MRSA suspected:

  • Add vancomycin or linezolid to standard therapy 1

Dosing and Duration

• Standard CAP duration: Minimum of 5 days when clinical stability is achieved 1
• Levofloxacin dosing: 750 mg once daily for 5 days OR 500 mg once daily for 7-14 days 2, 5
• Azithromycin dosing: 500 mg on day 1, followed by 250 mg once daily on days 2-5 6
• Clinical stability criteria: Resolution of vital sign abnormalities, ability to eat, and normal mentation 1

Monitoring Response to Treatment

• Fever should resolve within 2-3 days after starting antibiotics
• Treatment failure is indicated by:
  • Persistent fever beyond 3 days
  • Worsening respiratory symptoms
  • Progression of pulmonary infiltrates 1

Important Caveats and Pitfalls

• Avoid cefixime for respiratory infections due to poor activity against S. pneumoniae 1
• Narrow-spectrum agents should be used when possible to reduce "collateral damage" (superinfection by resistant pathogens) 7
• De-escalate therapy after 48-72 hours if clinical response is adequate and no evidence of bacterial superinfection 1
• Switch from IV to oral therapy when patients are:
  • Hemodynamically stable
  • Clinically improving
  • Able to ingest medications
  • Have normally functioning GI tract 1
• Maintain oxygen saturation >92% in uncomplicated cases 1

By following these evidence-based recommendations, clinicians can effectively treat CAP while minimizing antibiotic resistance and optimizing patient outcomes.