What is the recommended treatment for bacterial pneumonia?

Treatment of Bacterial Pneumonia

The recommended treatment for bacterial pneumonia should be empirical and follow an approach based on the individual risk of mortality, with antimicrobial treatment initiated immediately after diagnosis. 1

Classification and Initial Assessment

Treatment should be classified according to severity:

• Mild (ambulatory treatment)
• Moderate (hospital ward)
• Severe (ICU)

Initial Empirical Treatment Recommendations

For Outpatient/Ambulatory Treatment:

• First-line for adults over 40 or suspected pneumococcal origin: Oral amoxicillin 3 g/day 1
• First-line for adults under 40 with suspected atypical pathogens: Oral macrolides 1

For Hospitalized Patients with Non-Severe Pneumonia:

• Aminopenicillin ± macrolide
• Aminopenicillin/β-lactamase inhibitor ± macrolide
• Non-antipseudomonal cephalosporin (cefotaxime or ceftriaxone) ± macrolide
• Levofloxacin or moxifloxacin (respiratory fluoroquinolones)
• Penicillin G ± macrolide 1

For Severe Pneumonia (ICU patients):

• Without P. aeruginosa risk factors: Non-antipseudomonal cephalosporin III + macrolide OR moxifloxacin/levofloxacin ± non-antipseudomonal cephalosporin III 1
• With P. aeruginosa risk factors: Antipseudomonal cephalosporin OR acylureidopenicillin/β-lactamase inhibitor OR carbapenem PLUS ciprofloxacin OR PLUS macrolide + aminoglycoside 1

Route of Administration

• Oral route is recommended for non-severe pneumonia when there are no contraindications 1
• Parenteral (IV) therapy should be used for severe pneumonia 1
• Sequential therapy (IV to oral) should be considered in all hospitalized patients when:
  • Clinical improvement occurs
  • Temperature has been normal for 24 hours
  • No contraindication to oral route exists 1

Duration of Treatment

• For non-severe pneumonia: 7-8 days in responding patients 1
• For severe pneumonia with no identified pathogen: 10 days 1
• For specific pathogens:
  • Legionella, staphylococcal, or Gram-negative enteric bacilli: 14-21 days 1
• Biomarkers, particularly procalcitonin (PCT), may guide shorter treatment duration 1

Pathogen-Specific Treatment

For specific pathogens when identified:

• Streptococcus pneumoniae: Amoxicillin or penicillin G (first choice) 1
• Chlamydophila pneumoniae: Doxycycline, macrolide, levofloxacin, or moxifloxacin 1
• Legionella spp.: Levofloxacin, moxifloxacin, or macrolide (azithromycin preferred) ± rifampicin 1
• Pseudomonas aeruginosa: Combination therapy with antipseudomonal β-lactam plus either ciprofloxacin or aminoglycoside 1, 2
• Acinetobacter baumannii: Third-generation cephalosporin + aminoglycoside or ampicillin-sulbactam 1

Management of Treatment Failure

If a patient fails to improve as expected:

1. Review clinical history, examination, and investigation results
2. Consider further investigations (repeat chest radiograph, CRP, WBC, microbiological testing)
3. For non-severe pneumonia on amoxicillin monotherapy: Add or substitute a macrolide
4. For non-severe pneumonia on combination therapy: Consider changing to a respiratory fluoroquinolone
5. For severe pneumonia not responding to combination therapy: Consider adding rifampicin 1

Special Considerations

• Levofloxacin can be used as a 5-day, high-dose (750 mg daily) regimen for community-acquired pneumonia 2, 3
• Short-course antibiotic regimens (≤7 days) have been shown to be as effective as longer courses for mild to moderate CAP 4
• Early mobilization is recommended for all patients 1
• Low molecular weight heparin should be given to patients with acute respiratory failure 1

Common Pitfalls to Avoid

1. Delayed antibiotic administration: Treatment should begin immediately after diagnosis 1
2. Inappropriate route selection: Oral therapy is appropriate for non-severe cases; parenteral for severe cases
3. Excessive treatment duration: Most cases respond to 7-8 days of appropriate therapy 1
4. Failure to switch from IV to oral therapy: Switch when clinically improved and afebrile for 24 hours 1
5. Inadequate coverage for suspected pathogens: Consider local resistance patterns and patient risk factors
6. Not adjusting therapy when culture results become available: De-escalate to targeted therapy when possible

By following these evidence-based recommendations, clinicians can effectively treat bacterial pneumonia while minimizing antibiotic resistance, adverse effects, and healthcare costs.