What are the treatment options for community-acquired pneumonia (CAP)?

Treatment Options for Community-Acquired Pneumonia

For community-acquired pneumonia (CAP), treatment should be based on patient risk factors, severity of illness, and setting of care, with empiric antibiotic therapy tailored to cover the most likely pathogens while considering local resistance patterns. 1

Outpatient Treatment

Healthy Adults Without Comorbidities

• First choice: Amoxicillin 1 g three times daily (strong recommendation, moderate quality evidence) 1
• Alternative options:
  • Doxycycline 100 mg twice daily (conditional recommendation, low quality evidence) 1
  • Macrolides (azithromycin 500 mg on first day then 250 mg daily or clarithromycin 500 mg twice daily) only in areas with pneumococcal resistance to macrolides <25% (conditional recommendation) 1

Adults With Comorbidities

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

• Combination therapy options:

  • Amoxicillin/clavulanate (500/125 mg three times daily, 875/125 mg twice daily, or 2000/125 mg twice daily) OR a cephalosporin (cefpodoxime 200 mg twice daily or cefuroxime 500 mg twice daily)
  • PLUS a macrolide (azithromycin 500 mg on first day then 250 mg daily, clarithromycin 500 mg twice daily) or doxycycline 100 mg twice daily 1

• Monotherapy option:

  • Respiratory fluoroquinolone (levofloxacin 750 mg daily, moxifloxacin 400 mg daily, or gemifloxacin 320 mg daily) 1, 2

Inpatient Treatment (Non-ICU)

• Preferred regimen:
  • β-lactam (ampicillin/sulbactam, cefotaxime, ceftriaxone, or ceftaroline) PLUS a macrolide (azithromycin or clarithromycin) 1
  • OR a respiratory fluoroquinolone alone (levofloxacin, moxifloxacin) 1

Severe CAP Requiring ICU Care

Without Risk Factors for Pseudomonas aeruginosa

• Combination therapy:
  • Non-antipseudomonal β-lactam (ceftriaxone, cefotaxime) PLUS either a macrolide or a respiratory fluoroquinolone 1

With Risk Factors for Pseudomonas aeruginosa

• Combination therapy:
  • Antipseudomonal β-lactam (cefepime, ceftazidime, piperacillin-tazobactam, meropenem) PLUS either:
    • Ciprofloxacin OR
    • Macrolide plus aminoglycoside (gentamicin, tobramycin, or amikacin) 1

Special Considerations

MRSA Risk Factors

• Add MRSA coverage (vancomycin or linezolid) and obtain cultures/nasal PCR to allow de-escalation 1

Duration of Therapy

• Generally 5-7 days for responding patients 1
• Shorter courses (minimum 3 days) may be appropriate for patients who show clinical improvement 3
• Procalcitonin levels may guide shorter treatment duration 1

Pathogen-Specific Considerations

Atypical Pathogens

• For suspected or confirmed Legionella: Respiratory fluoroquinolone (levofloxacin preferred) or macrolide (azithromycin preferred) ± rifampin 1
• For Mycoplasma or Chlamydophila: Macrolide, doxycycline, or respiratory fluoroquinolone 1

Drug-Resistant S. pneumoniae

• Levofloxacin has shown 95% clinical and bacteriological success against multi-drug resistant S. pneumoniae 2

Common Pitfalls and Caveats

• Delayed antibiotic administration: Antibiotics should be initiated immediately after diagnosis of CAP to reduce mortality 1
• Overuse of fluoroquinolones: Reserve respiratory fluoroquinolones for patients with comorbidities or risk factors for resistant pathogens to prevent development of resistance 1, 4
• Inadequate coverage: Failure of initial empiric therapy to cover causative pathogens is associated with worse outcomes 5
• Procalcitonin misinterpretation: While procalcitonin can guide duration of therapy, it should not be used to withhold initial antibiotic therapy in patients with clinically suspected and radiographically confirmed CAP 1
• Inadequate severity assessment: Use validated severity tools (2007 IDSA/ATS criteria) to guide site-of-care decisions and treatment intensity 1

Emerging Therapies

• Newer antibiotics with activity against resistant pathogens include delafloxacin, omadacycline, lefamulin, and nemonoxacin 5, 6
• These agents may be particularly valuable for treating methicillin-resistant S. aureus and macrolide-resistant S. pneumoniae 5