What are the recommended antibiotics for community-acquired pneumonia?

Recommended Antibiotics for Community-Acquired Pneumonia

For community-acquired pneumonia (CAP), the recommended first-line treatment is either a respiratory fluoroquinolone or a beta-lactam plus macrolide combination, with specific regimens based on patient setting and risk factors. 1

Outpatient Treatment

Patients without comorbidities:

• Macrolide (azithromycin, clarithromycin, or erythromycin) as first-line therapy 1, 2
• Doxycycline 100mg twice daily as an alternative 1, 2

Patients with comorbidities (chronic heart/lung/liver/renal disease, diabetes, alcoholism, malignancy, immunosuppression, or recent antibiotic use):

• A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin 750mg) 1
• OR a beta-lactam plus a macrolide 1
  • Preferred beta-lactams: high-dose amoxicillin (1g three times daily) or amoxicillin-clavulanate (2g twice daily) 1, 2
  • Alternative beta-lactams: ceftriaxone, cefpodoxime, or cefuroxime (500mg twice daily) 1

Inpatient Treatment (Non-ICU)

• A respiratory fluoroquinolone (levofloxacin 750mg daily or moxifloxacin 400mg daily) 1
• OR a beta-lactam (ampicillin-sulbactam, cefotaxime, ceftriaxone, or ampicillin) plus a macrolide (azithromycin or clarithromycin) 1
• For penicillin-allergic patients, use a respiratory fluoroquinolone 1

Inpatient Treatment (ICU)

• A beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone 1
• For patients at risk for Pseudomonas infection: an antipseudomonal beta-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either a fluoroquinolone or an aminoglycoside plus azithromycin 1
• For suspected methicillin-resistant Staphylococcus aureus (MRSA), add vancomycin or linezolid 1

Duration of Therapy

• Minimum 5 days of antibiotic treatment 1, 2
• Patient should be afebrile for 48-72 hours before discontinuing antibiotics 1
• Intravenous to oral switch when patient is hemodynamically stable, improving clinically, and able to take oral medications 1

Special Considerations

Regional Resistance Patterns

• In regions with high rates (>25%) of macrolide-resistant S. pneumoniae, consider alternative agents even for patients without comorbidities 1
• Local resistance patterns should guide empiric therapy choices 1, 3

Atypical Pathogens

• Macrolides, doxycycline, and respiratory fluoroquinolones provide coverage for atypical pathogens (Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila) 4, 3
• For suspected Legionella pneumonia, consider extended treatment up to 21 days 2

Common Pitfalls to Avoid

• Monotherapy with macrolides should be limited to young, healthy patients without risk factors due to increasing resistance rates 1, 3
• Overuse of fluoroquinolones can drive resistance; reserve for appropriate indications and patients with comorbidities 1, 2
• Delayed antibiotic administration increases mortality; first dose should be given promptly, especially in the emergency department 1
• Inadequate duration of therapy can lead to treatment failure; ensure minimum of 5 days and clinical improvement before discontinuation 1
• Failure to adjust therapy when culture results become available; switch to pathogen-directed therapy when possible 1

By following these evidence-based recommendations, clinicians can optimize outcomes while minimizing antibiotic resistance in the treatment of community-acquired pneumonia.