What are the treatment options for Community-Acquired Pneumonia (CAP)?

Treatment Options for Community-Acquired Pneumonia (CAP)

For patients with community-acquired pneumonia, treatment should be based on severity of illness, with outpatients receiving either amoxicillin or doxycycline, and hospitalized patients receiving either combination therapy with a β-lactam plus a macrolide or monotherapy with a respiratory fluoroquinolone. 1

Outpatient Treatment

Patients without comorbidities:

• First-line options:
  • Amoxicillin 1 g every 8 hours 1
  • Doxycycline 100 mg twice daily (consider 200 mg for first dose) 1

Patients with comorbidities:

• First-line options:
  • Combination therapy: β-lactam (amoxicillin/clavulanate) plus a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily) 1, 2
  • Monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1, 2

Inpatient Treatment (Non-ICU)

• First-line options:

  • Combination therapy: β-lactam (ampicillin/sulbactam 1.5-3 g every 6h, cefotaxime 1-2 g every 8h, or ceftriaxone 1-2 g daily) plus a macrolide (azithromycin 500 mg daily) 1, 2
  • Monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1

• Alternative option (for patients with contraindications to both macrolides and fluoroquinolones):

  • Combination therapy: β-lactam plus doxycycline 100 mg twice daily 1

Severe CAP (ICU Treatment)

• Without risk factors for Pseudomonas aeruginosa:

  • Non-antipseudomonal cephalosporin (ceftriaxone) plus macrolide OR
  • Respiratory fluoroquinolone (moxifloxacin or levofloxacin) ± non-antipseudomonal cephalosporin 1

• With risk factors for Pseudomonas aeruginosa:

  • Antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, meropenem) plus either:
    • Ciprofloxacin OR
    • Macrolide plus aminoglycoside 1, 3

Duration of Treatment

• Generally 5-7 days for most uncomplicated cases 2
• Treatment should not exceed 8 days in responding patients 1
• Patient should be afebrile for 48-72 hours and have no more than one sign of clinical instability before discontinuing treatment 2

Pathogen-Specific Treatment

Pathogen	Preferred Treatment
Streptococcus pneumoniae	β-lactams (amoxicillin, cefotaxime, ceftriaxone) [2]
Mycoplasma pneumoniae	Macrolide (azithromycin preferred) [2]
Legionella spp.	Levofloxacin (preferred), moxifloxacin, or macrolide ± rifampicin [1,2]
Chlamydophila pneumoniae	Doxycycline, macrolide, levofloxacin, or moxifloxacin [1,2]

Important Considerations

Treatment Failure

• Consider treatment failure if no response is seen within 3-5 days 2
• Possible causes include incorrect diagnosis, inappropriate antibiotic, unusual pathogen, or complications 2

Antibiotic Selection Principles

1. Prior antibiotic exposure: Patients with recent exposure to one class of antibiotics should receive treatment from a different class 1
2. Penicillin allergy: Respiratory fluoroquinolones are recommended as first-line treatment for patients with penicillin allergy 2
3. Azithromycin warnings: Be aware of potential for QT prolongation, especially in patients with cardiac risk factors 4

Common Pitfalls to Avoid

• Inadequate coverage for atypical pathogens: Ensure coverage for both typical and atypical pathogens 2
• Excessive treatment duration: Most uncomplicated CAP can be treated for 5-7 days 2
• Delayed switch from IV to oral therapy: Early conversion facilitates discharge and reduces costs without compromising outcomes 2
• Overuse of broad-spectrum antibiotics: Consider narrowing therapy once pathogens are identified to reduce resistance development 2
• Failure to recognize resistant pathogens: Be aware of local resistance patterns, especially for S. pneumoniae 2

The evidence strongly supports that appropriate empiric antibiotic therapy significantly reduces morbidity and mortality in CAP. The choice between combination therapy and monotherapy should be guided by patient factors, local resistance patterns, and severity of illness.