What are the guidelines for pneumonia treatment?

Pneumonia Treatment Guidelines

Community-Acquired Pneumonia (CAP)

Outpatient Management (Mild Disease)

For outpatients with mild CAP, amoxicillin is the preferred first-line agent, with macrolides (erythromycin or clarithromycin) as alternatives for penicillin-allergic patients. 1

• Amoxicillin should be used at higher doses than previously recommended for optimal coverage of Streptococcus pneumoniae 1
• Macrolide monotherapy (azithromycin, clarithromycin, or erythromycin) is an alternative choice, though azithromycin susceptibility rates for S. pneumoniae are low in some regions like Taiwan 1
• For children under 5 years, amoxicillin remains first choice due to effectiveness against common pathogens, tolerability, and cost 1
• In children aged 5 and above, macrolides may be used as first-line empirical treatment given higher prevalence of Mycoplasma pneumoniae 1

Hospitalized Patients (Non-ICU, Moderate Severity)

For hospitalized patients with moderate severity CAP (CURB-65 score 2-3), combination therapy with a β-lactam antibiotic plus a macrolide is recommended. 1, 2

• Preferred regimen: Ceftriaxone combined with azithromycin for minimum 3 days 2
• Alternative: Fluoroquinolone (levofloxacin or moxifloxacin) monotherapy 1
• Avoid tigecycline: FDA boxed warning exists due to increased all-cause mortality; infectious disease consultation recommended if considering use 1
• For patients with risk factors for drug-resistant S. pneumoniae, use high-dose amoxicillin, amoxicillin/clavulanate, cefuroxime, ceftriaxone, cefotaxime, or ampicillin/sulbactam 1

Severe CAP (ICU Admission)

Patients with severe CAP requiring ICU admission should receive combination therapy with a broad-spectrum β-lactam plus either a macrolide or fluoroquinolone. 1, 3

• Preferred regimens:
  • Cefotaxime or ceftriaxone PLUS macrolide 1, 3
  • Piperacillin/tazobactam PLUS macrolide 1, 3
• Alternative: Non-antipseudomonal cephalosporin III plus moxifloxacin or levofloxacin 1
• For Pseudomonas risk factors: Use antipseudomonal β-lactam (piperacillin/tazobactam, cefepime, ceftazidime, meropenem, or imipenem) PLUS ciprofloxacin OR macrolide plus aminoglycoside 1
• Systemic corticosteroids administered within 24 hours of severe CAP development may reduce 28-day mortality 2

Hospital-Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Low Risk for Multidrug-Resistant Organisms (MDRO)

For HAP/VAP with low MDRO risk and stable hemodynamics, monotherapy with an antipseudomonal agent is appropriate. 1

• Options include:
  • Piperacillin/tazobactam 4.5 g IV q6h 1, 4
  • Cefoperazone/sulbactam 4 g IV q12h 1
  • Ceftazidime 2 g IV q8h 1
  • Cefepime 2 g IV q8h 1
  • Meropenem 1 g IV q8h 1
  • Imipenem 500 mg IV q6h 1
  • Levofloxacin 750 mg IV daily 1, 5
  • Ciprofloxacin 400 mg IV q8h 1

High Risk for MDRO or Unstable Hemodynamics

For HAP/VAP with high MDRO risk or unstable hemodynamics, use combination therapy with an antipseudomonal β-lactam plus either a fluoroquinolone or aminoglycoside. 1

• Base regimen: Same antipseudomonal agents as above 1
• PLUS one of:
  • Gentamicin 5-7 mg/kg IV daily 1
  • Amikacin 15-20 mg/kg IV daily 1
  • Colistin 5 mg/kg IV loading dose, then 2.5 mg × (1.5 × CrCl + 30) IV q12h 1

Risk factors for MDRO include: septic shock at HAP/VAP onset, ARDS preceding HAP/VAP, acute renal replacement therapy prior to onset, previous MDRO colonization, and structural lung diseases like bronchiectasis 1

MRSA Coverage

When MRSA risk is present, add anti-MRSA therapy to gram-negative coverage. 1

• Options:
  • Vancomycin 25-30 mg/kg IV q8-12h 1
  • Teicoplanin 6-12 mg/kg IV q12h × 3 doses, then 6-12 mg/kg IV daily (use 12 mg/kg for severe disease or high MIC settings) 1
  • Linezolid 600 mg IV q12h 1

Treatment Duration and Monitoring

Patients with CAP should be treated for minimum 5 days, be afebrile for 48-72 hours, and have no more than one CAP-associated sign of clinical instability before discontinuing therapy. 1

• Duration generally should not exceed 8 days in responding patients 1
• Longer duration (15 days) appropriate for Pseudomonas aeruginosa infections 3
• Switch to oral therapy when hemodynamically stable, clinically improving, able to ingest medications, and have functioning GI tract 1
• Inpatient observation after switching to oral therapy is unnecessary 1

Clinical monitoring should include: temperature, respiratory rate, pulse, blood pressure, mental status, oxygen saturation, and inspired oxygen concentration at least twice daily (more frequently in severe cases) 1

Special Considerations

Antibiotic Administration Timing

For hospitalized patients admitted through the emergency department, the first antibiotic dose should be administered while still in the ED. 1

• All admitted patients should receive first antibiotic dose within 8 hours of hospital arrival 1

Oxygen Therapy

All patients should receive appropriate oxygen therapy with monitoring to maintain PaO₂ >8 kPa and SaO₂ >92%. 1

• High oxygen concentrations can safely be given in uncomplicated pneumonia 1
• In COPD patients with ventilatory failure, oxygen therapy should be guided by repeated arterial blood gas measurements 1

Follow-Up

Clinical review should be arranged at approximately 6 weeks post-discharge, either with the general practitioner or in hospital clinic. 1

• Chest radiograph need not be repeated prior to discharge in patients with satisfactory clinical recovery 1
• Repeat chest radiograph at 6-week follow-up for patients with persistent symptoms or radiological abnormalities 1
• Further investigations including bronchoscopy should be considered for persisting signs, symptoms, and radiological abnormalities 6 weeks after completing treatment 1

Prevention

Pneumococcal and influenza vaccines should be administered to appropriate at-risk populations. 1

• Smoking cessation should be promoted in all patients 1
• All patients with CAP should be tested for COVID-19 and influenza when these viruses are common in the community 2