What are the recommended antibiotics for Community-Acquired Pneumonia (CAP)?

Recommended Antibiotics for Community-Acquired Pneumonia (CAP)

For outpatient treatment of CAP, amoxicillin 1g three times daily is the first-line therapy for healthy adults without comorbidities, while combination therapy with a β-lactam plus a macrolide or monotherapy with a respiratory fluoroquinolone is recommended for those with comorbidities. 1

Outpatient Treatment

Healthy Adults Without Comorbidities

• Amoxicillin 1g three times daily (strong recommendation, moderate quality evidence) 2, 1
• Doxycycline 100mg twice daily (conditional recommendation, low quality evidence) 2, 1
• Macrolides (azithromycin 500mg on first day then 250mg daily, or clarithromycin 500mg twice daily) only in areas where pneumococcal resistance to macrolides is <25% (conditional recommendation) 2, 1

Adults With Comorbidities

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

Option 1: Combination Therapy

• β-lactam (one of the following):
  • Amoxicillin-clavulanate 500mg/125mg three times daily, or 875mg/125mg twice daily, or 2,000mg/125mg twice daily 2, 1
  • Cefpodoxime 200mg twice daily 2, 1
  • Cefuroxime 500mg twice daily 2, 1

PLUS

• Macrolide (azithromycin 500mg on first day then 250mg daily, or clarithromycin 500mg twice daily) 2, 1
• OR doxycycline 100mg twice daily 2, 1

Option 2: Monotherapy

• Respiratory fluoroquinolone:
  • Levofloxacin 750mg daily 2, 3
  • Moxifloxacin 400mg daily 2, 1
  • Gemifloxacin 320mg daily 2, 1

Inpatient Treatment (Non-ICU)

• β-lactam (ampicillin-sulbactam, cefotaxime, ceftriaxone) plus a macrolide (strong recommendation) 2, 1
• OR respiratory fluoroquinolone monotherapy (levofloxacin or moxifloxacin) (strong recommendation) 2, 1
• OR β-lactam plus doxycycline (conditional recommendation) 1

Inpatient Treatment (ICU)

• β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone (strong recommendation) 2, 1
• For penicillin-allergic patients: respiratory fluoroquinolone plus aztreonam 2, 1

Special Considerations

Pseudomonas Risk Factors

For patients with risk factors for Pseudomonas infection:

• Antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either:
  • Ciprofloxacin or levofloxacin (750mg) 2, 1
  • OR an aminoglycoside plus azithromycin 2, 1
  • OR an aminoglycoside plus an antipneumococcal fluoroquinolone 2, 1

Community-Acquired MRSA

• Add vancomycin or linezolid to the standard regimen 2, 1

Duration of Therapy

• Standard duration: 5-7 days for uncomplicated CAP 2, 1
• Duration should generally not exceed 8 days in a responding patient 2

Important Clinical Considerations

• Administer the first antibiotic dose as soon as possible after diagnosis of CAP 2, 1
• Switch from IV to oral therapy when patients are hemodynamically stable, clinically improving, able to take oral medications, and have normal GI function 1
• Macrolide monotherapy should be avoided in areas with high rates (>25%) of macrolide-resistant S. pneumoniae 2, 1
• Consider patient-specific factors such as recent antibiotic exposure, which may increase the risk of resistant organisms 1

Common Pitfalls to Avoid

• Delaying antibiotic administration in hospitalized patients, which can increase mortality risk 2, 1
• Using macrolide monotherapy in areas with high resistance rates 2, 1
• Failing to adjust therapy when culture results become available 1
• Not considering the potential for Pseudomonas or MRSA in patients with specific risk factors 2, 1
• Overlooking the importance of local resistance patterns when selecting empiric therapy 2, 4
• Continuing IV antibiotics longer than necessary when patients meet criteria for oral therapy 1, 5

The choice of antibiotic regimen should be guided by local resistance patterns, patient risk factors, and severity of illness to ensure optimal outcomes while minimizing the development of antibiotic resistance 2, 1.