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

Treatment for Community-Acquired Pneumonia

For community-acquired pneumonia, treatment should be based on patient characteristics, with amoxicillin as first-line therapy for healthy outpatients, combination therapy or respiratory fluoroquinolones for those with comorbidities, and β-lactam plus macrolide or respiratory fluoroquinolone for hospitalized patients. 1

Outpatient Treatment

Healthy Adults Without Comorbidities

• Amoxicillin 1 g three times daily (strong recommendation, moderate quality evidence) 1
• Doxycycline 100 mg twice daily (conditional recommendation, low quality evidence) 1
• Macrolides (only in areas with pneumococcal resistance <25%):
  • Azithromycin 500 mg on first day then 250 mg daily, or
  • Clarithromycin 500 mg twice daily or extended release 1,000 mg daily 1

Adults With Comorbidities

Comorbidities include chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; or asplenia 1

Option 1: Combination therapy

• β-lactam:
  • Amoxicillin/clavulanate 500 mg/125 mg three times daily, or
  • Amoxicillin/clavulanate 875 mg/125 mg twice daily, or
  • Amoxicillin/clavulanate 2,000 mg/125 mg twice daily, or
  • Cephalosporin (cefpodoxime 200 mg twice daily or cefuroxime 500 mg twice daily)

PLUS

• Macrolide (azithromycin 500 mg on first day then 250 mg daily, clarithromycin 500 mg twice daily or extended release 1,000 mg daily) or
• Doxycycline 100 mg twice daily 1

Option 2: Monotherapy

• Respiratory fluoroquinolone:
  • Levofloxacin 750 mg daily, or
  • Moxifloxacin 400 mg daily, or
  • Gemifloxacin 320 mg daily 1

Inpatient Treatment

Non-Severe CAP Without Risk Factors for MRSA or P. aeruginosa

• β-lactam (ampicillin + sulbactam 1.5-3 g every 6h, cefotaxime 1-2 g every 8h, ceftriaxone 1-2 g daily, or ceftaroline 600 mg every 12h) plus macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily), or
• Respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1, 2
• Alternative: β-lactam plus doxycycline 100 mg twice daily (if contraindications to both macrolides and fluoroquinolones) 1

Severe CAP Without Risk Factors for MRSA or P. aeruginosa

• β-lactam plus macrolide (strong recommendation, moderate quality evidence), or
• β-lactam plus respiratory fluoroquinolone (strong recommendation, low quality evidence) 1

Important Considerations

• Recent antibiotic exposure: Patients with recent exposure to one class of antibiotics should receive treatment with antibiotics from a different class due to increased risk for bacterial resistance 1

• Duration of therapy: Minimum 3 days for hospitalized patients with bacterial CAP, with clinical improvement before discontinuation 2

• Diagnostic testing: For severe CAP, testing for pneumococcal and Legionella urinary antigens is recommended 1

• Safety concerns:

  • Macrolides: Risk of QT prolongation, especially in elderly patients or those with cardiac conditions 3
  • Fluoroquinolones: FDA warnings regarding tendon rupture, peripheral neuropathy, and central nervous system effects 1, 4

• Efficacy data: Clinical trials have shown comparable efficacy between shorter courses of azithromycin and longer courses of amoxicillin-clavulanate or clarithromycin 5, 6

Common Pitfalls to Avoid

• Underestimating severity: Use severity assessment tools (2007 IDSA/ATS criteria) to guide site-of-care decisions and treatment intensity 1

• Inappropriate antibiotic selection: Macrolide monotherapy should only be used in areas with pneumococcal resistance <25% 1

• Failure to consider resistant pathogens: Patients with risk factors for MRSA or P. aeruginosa require specific antibiotic coverage 1

• Inadequate diagnostic testing: For severe CAP, consider testing for specific pathogens including Legionella and S. pneumoniae 1

• Overlooking comorbidities: Patients with underlying conditions require broader antibiotic coverage 1, 2