What are the treatment options for pneumonia?

Treatment of Pneumonia

Antibiotic treatment should be initiated immediately upon diagnosis of pneumonia, with empiric regimen selection based on severity and treatment setting. 1

Treatment Setting and Severity Assessment

The first critical decision is determining the appropriate treatment setting, which directly guides antibiotic selection 1:

• Ambulatory/Outpatient: Mild pneumonia appropriate for oral therapy from the start 1
• Hospital Ward: Moderate pneumonia requiring hospitalization but not ICU-level care 1
• ICU/Severe: Severe pneumonia with respiratory failure, septic shock, or multiple organ dysfunction 1

Empiric Antibiotic Regimens by Setting

Outpatient/Ambulatory Pneumonia

For outpatients, oral therapy can be initiated from the beginning 1:

• Preferred options (in alphabetical order): 1

  • Aminopenicillin ± macrolide
  • Aminopenicillin/β-lactamase inhibitor ± macrolide
  • Levofloxacin (respiratory fluoroquinolone)
  • Moxifloxacin (respiratory fluoroquinolone)

• For patients with comorbidities or recent antibiotic use: Combination therapy with β-lactam plus macrolide OR respiratory fluoroquinolone monotherapy is recommended 2, 3

Hospitalized Non-ICU Patients

For hospitalized ward patients, combination therapy is strongly recommended 1, 2:

• First-line regimens (Level I evidence): 2

  • β-lactam (ceftriaxone, cefotaxime, or ampicillin) PLUS macrolide (azithromycin or clarithromycin)
  • Alternative: Respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily or moxifloxacin)

• Additional options: 1

  • Aminopenicillin/β-lactamase inhibitor ± macrolide
  • Penicillin G ± macrolide
  • Non-antipseudomonal cephalosporin III ± macrolide

• Important note: New macrolides (azithromycin, clarithromycin) are preferred over erythromycin 1

Severe ICU-Level Pneumonia

For severe pneumonia requiring ICU admission, immediate intravenous broad-spectrum combination therapy is mandatory 1, 2:

Without Pseudomonas Risk Factors:

• Non-antipseudomonal cephalosporin III (ceftriaxone or cefotaxime) PLUS macrolide 1
• Alternative: Moxifloxacin or levofloxacin ± non-antipseudomonal cephalosporin III 1

With Pseudomonas Risk Factors:

Use antipseudomonal coverage with dual therapy 1:

• Antipseudomonal β-lactam (piperacillin-tazobactam, ceftazidime, or meropenem—preferred up to 6g daily) 1, 2
• PLUS ciprofloxacin 1, 2
• OR PLUS macrolide + aminoglycoside (gentamicin, tobramycin, or amikacin) 1, 2

Critical caveat: If using ceftazidime, it must be combined with penicillin G for adequate Streptococcus pneumoniae coverage 1

Pathogen-Specific Therapy

When specific pathogens are identified, targeted therapy should be used 1:

Atypical Pathogens:

• Legionella species: Levofloxacin (most data available) or moxifloxacin; alternative is azithromycin ± rifampicin 1
• Chlamydophila pneumoniae: Doxycycline, macrolide, levofloxacin, or moxifloxacin 1
• Mycoplasma pneumoniae: Macrolides, doxycycline, or respiratory fluoroquinolones 1, 4
• Coxiella burnetii: Doxycycline, levofloxacin, or moxifloxacin 1

Aspiration Pneumonia:

Empiric coverage should include anaerobes 1:

• Hospital ward (from home): β-lactam/β-lactamase inhibitor, clindamycin, or moxifloxacin 1
• ICU or nursing home admission: Clindamycin + cephalosporin 1

Route of Administration and IV-to-Oral Switch

Intravenous therapy should be started for all hospitalized patients, particularly those with hemodynamic instability or severe respiratory compromise 1, 2:

• Switch to oral therapy when: 1, 2

  • Patient is hemodynamically stable
  • Clinically improving
  • Afebrile for 24 hours
  • Able to tolerate oral intake

• Sequential therapy using the same drug class is recommended 1

• Most patients do not need to remain hospitalized after switching to oral therapy 1

• This approach is safe even in severe pneumonia once clinical stability is achieved 1

Duration of Treatment

Treatment should generally not exceed 8 days in a responding patient 1, 2:

• Standard duration: 7-8 days for responding patients 2

• Extended duration (10-21 days) required for: 1, 5, 2

  • Severe pneumonia (10 days minimum)
  • Legionella infections (14-21 days)
  • Staphylococcal infections (14-21 days)
  • Gram-negative enteric bacilli (14-21 days)

• Patients must be afebrile for 48-72 hours before discontinuing antibiotics 5, 2

• Biomarkers, particularly procalcitonin (PCT), may guide shorter treatment duration 1

Management of Treatment Failure

If the patient does not respond within 48-72 hours, immediate reassessment is mandatory 5, 2:

Reassessment Steps:

• Obtain repeat chest radiograph 5, 2
• Check C-reactive protein (CRP) and white blood cell count 5
• Collect additional microbiological specimens (sputum culture, blood cultures, urinary antigens) 5, 2
• Review by experienced clinician examining clinical history, physical findings, and all investigation results 5

Antibiotic Modification Strategy:

For non-severe pneumonia previously on amoxicillin monotherapy: Add or substitute a macrolide (clarithromycin or erythromycin) to cover atypical pathogens 5

For non-severe pneumonia on combination therapy: Switch to respiratory fluoroquinolone (levofloxacin 500-750 mg daily) 5

For severe pneumonia not responding to combination therapy: Consider adding rifampicin to the existing regimen 5

Critical Pitfalls to Avoid

• Never use azithromycin as monotherapy in patients with risk factors for drug-resistant S. pneumoniae (age >65, comorbidities, recent antibiotics, immunosuppression) 2, 6

• Do not use azithromycin in patients judged inappropriate for oral therapy due to moderate-to-severe illness, cystic fibrosis, nosocomial acquisition, known/suspected bacteremia, hospitalization requirement, elderly/debilitated status, or immunodeficiency 6

• Avoid continuing the same antibiotic regimen beyond 48-72 hours without clinical improvement—this mandates investigation for resistant organisms, complications, or non-infectious mimics 5, 2

• Do not use the same antibiotic class if the patient recently received it 2

• Macrolide monotherapy should be avoided in hospitalized patients—combination therapy or fluoroquinolone monotherapy is required 2, 3

• Be aware of QT prolongation risk with macrolides and fluoroquinolones, particularly in elderly patients, those with cardiac conditions, electrolyte abnormalities, or on other QT-prolonging medications 6

Additional Supportive Therapies

Beyond antibiotics, several adjunctive measures improve outcomes 1:

• Early mobilization for all patients 1
• Low molecular weight heparin for patients with acute respiratory failure 1
• Non-invasive ventilation can be considered, particularly in COPD patients 1
• Steroids are NOT recommended in routine pneumonia treatment 1

Follow-Up

Arrange clinical review at approximately 6 weeks with repeat chest radiograph for patients with persistent symptoms, physical signs, or higher risk of underlying malignancy 5