What is the recommended treatment for pneumonia?

Recommended Treatment for Pneumonia

For community-acquired pneumonia (CAP), the recommended first-line treatment is a β-lactam (ceftriaxone 1-2g IV daily) plus a macrolide (azithromycin 500mg IV/PO daily) for hospitalized patients, or amoxicillin (500-1000 mg PO every 8 hours) for outpatient treatment of mild to moderate cases. 1

Initial Treatment Selection Based on Setting

Outpatient Treatment

• First choice: Amoxicillin 500-1000 mg PO every 8 hours 1
• Alternatives:
  • Doxycycline 100 mg PO twice daily 1
  • Respiratory fluoroquinolones (levofloxacin or moxifloxacin) when there are clinically relevant bacterial resistance rates 1
  • Macrolides (in areas with low pneumococcal resistance) 1

Inpatient Treatment (Non-ICU)

• Standard regimen: Ceftriaxone 1-2g IV daily PLUS azithromycin 500mg IV/PO daily 1
  • Note: Ceftriaxone 1g daily is as effective as 2g daily for CAP treatment 2
• Duration: Minimum of 5 days, continue until patient has been afebrile for 48-72 hours and is clinically stable 1

Severe CAP/ICU Treatment

• Standard regimen: Ceftriaxone 1-2g IV daily PLUS azithromycin 500mg IV/PO daily 1
• For patients with risk factors for Pseudomonas aeruginosa:
  • Antipseudomonal β-lactam (ceftazidime, piperacillin-tazobactam, meropenem) PLUS either ciprofloxacin OR macrolide plus aminoglycoside 3
  • For nosocomial pneumonia with P. aeruginosa risk: Piperacillin-tazobactam 4.5g IV every 6 hours plus an aminoglycoside 4

Special Considerations

Aspiration Pneumonia

• Hospital ward, admitted from home:
  • Oral or IV β-lactam/β-lactamase inhibitor (e.g., amoxicillin-clavulanate)
  • Alternative: Clindamycin OR IV cephalosporin + oral metronidazole OR moxifloxacin 3
• ICU or admitted from nursing home:
  • Clindamycin + cephalosporin 3

Risk Factors for Drug-Resistant Pathogens

• MRSA risk factors: Prior MRSA infection/colonization, recent IV antibiotic use within 90 days, hospitalization in unit with high MRSA prevalence 1
  • Add vancomycin or linezolid to the regimen
• Pseudomonas risk factors: Severe COPD, bronchiectasis, recent antibiotic use 1
  • Use antipseudomonal coverage as noted above

Patients with Renal Impairment

• Adjust dosing based on creatinine clearance
• For piperacillin-tazobactam in patients with CrCl 20-40 mL/min: 2.25g every 6 hours (non-nosocomial) or 3.375g every 6 hours (nosocomial) 4

Treatment Duration

• Standard duration: 5 days if afebrile for 48-72 hours and clinically stable 1
• Extended durations:
  • 7-10 days for classical bacterial infection or uncomplicated CAP 1
  • 10-14 days for suspected M. pneumoniae or C. pneumoniae 1
  • 21 days for L. pneumophila, S. aureus, or severe CAP 1

Monitoring Response

• Clinical response should be assessed within 48-72 hours of initiating therapy 1
• Fever should resolve within 2-3 days after starting antibiotics 1
• C-reactive protein should be measured on days 1 and 3/4, especially with unfavorable clinical parameters 3
• Consider treatment failure if no improvement after 72 hours 3

Treatment Failure Management

• For non-responding pneumonia within first 72 hours: Consider antimicrobial resistance, unusual organism, or wrong diagnosis 3
• For non-response after 72 hours: Consider complications 3
• In unstable patients: Full reinvestigation and second empirical antimicrobial regimen 3

Switching from IV to Oral Therapy

• Switch when fever has resolved and clinical condition is stable 1
• In most patients, observation in hospital is not necessary after switching to oral treatment 3

Common Pitfalls to Avoid

1. Using macrolides as monotherapy in areas with high pneumococcal resistance
2. Failing to consider MRSA or P. aeruginosa in patients with risk factors
3. Treating for too short a duration in severe cases or specific pathogens
4. Not adjusting therapy when patients fail to respond within 72 hours
5. Overlooking the importance of early mobilization and thromboprophylaxis in hospitalized patients 3

By following these evidence-based recommendations, clinicians can provide optimal treatment for pneumonia while minimizing the risk of treatment failure and antimicrobial resistance.