What are the treatments for pneumonia?

Treatment of Pneumonia

Pneumonia treatment is stratified by severity and setting: mild community-acquired pneumonia (CAP) requires oral amoxicillin or macrolides, hospitalized non-severe CAP requires combination therapy with amoxicillin plus a macrolide, and severe CAP demands immediate intravenous broad-spectrum β-lactam plus macrolide therapy. 1

Treatment by Severity and Setting

Outpatient/Mild Community-Acquired Pneumonia

• Oral amoxicillin is the first-line agent for mild CAP, targeting Streptococcus pneumoniae, the most common pathogen 2
• Alternative regimens include macrolides (erythromycin, clarithromycin, or azithromycin) or doxycycline for patients with atypical pathogen coverage needs or penicillin allergy 1
• Treatment duration should be 7 days for uncomplicated pneumonia 2
• Macrolides or tetracyclines are preferred for Mycoplasma pneumoniae or Chlamydophila pneumoniae pneumonia 1, 3

Hospitalized Non-Severe Community-Acquired Pneumonia

• Combined oral therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) is preferred for patients requiring hospital admission for clinical reasons 1
• Most hospitalized patients with non-severe pneumonia can be adequately treated with oral antibiotics 1
• Amoxicillin monotherapy may be considered only for previously untreated patients or those admitted for non-clinical reasons (elderly, socially isolated) 1
• When oral treatment is contraindicated, use intravenous ampicillin or benzylpenicillin plus erythromycin or clarithromycin 1
• Fluoroquinolones with pneumococcal activity (levofloxacin) are alternative regimens for patients intolerant of penicillins or macrolides, though not recommended as first-line agents 1, 4

Severe Community-Acquired Pneumonia (ICU or High-Dependency)

• Patients with severe pneumonia should receive immediate parenteral antibiotics upon diagnosis 1, 2
• The preferred regimen is intravenous combination therapy: broad-spectrum β-lactamase stable antibiotic (co-amoxiclav, cefuroxime, cefotaxime, or ceftriaxone) plus a macrolide (clarithromycin or erythromycin) 1, 2
• For patients with risk factors for Pseudomonas aeruginosa, use antipseudomonal cephalosporin or acylureidopenicillin/β-lactamase inhibitor or carbapenem (meropenem preferred) PLUS ciprofloxacin OR macrolide plus aminoglycoside 1
• Treatment duration for severe pneumonia is 10 days, extended to 14-21 days if Legionella, staphylococcal, or gram-negative enteric bacilli are suspected or confirmed 1, 2
• For fluoroquinolone alternatives in severe cases, levofloxacin 750 mg/24h or 500 mg twice daily plus intravenous benzylpenicillin can be used 1

Nosocomial Pneumonia

• Combination therapy with extended-spectrum penicillin or cephalosporin plus aminoglycoside is commonly employed for ventilator-associated pneumonia 1
• For nosocomial pneumonia due to Pseudomonas aeruginosa, combination therapy with an anti-pseudomonal β-lactam is recommended 4
• Initial therapy must be directed at suspected pathogens based on the specific hospital's known susceptibility profile 1

Pathogen-Specific Therapy

When Specific Pathogens Are Identified

• Streptococcus pneumoniae: Penicillin G remains the drug of choice in the United States 1
• Legionella species: Levofloxacin or moxifloxacin (most data for levofloxacin), or macrolide (azithromycin preferred) ± rifampicin; erythromycin 2-4 g daily for at least 3 weeks 1, 3
• Mycoplasma pneumoniae* or *Chlamydophila pneumoniae: Macrolide (erythromycin) or doxycycline 200 mg daily 1, 3
• Haemophilus influenzae (non-β-lactamase-producing): Ampicillin or a cogener 1
• Methicillin-sensitive Staphylococcus aureus: Semisynthetic penicillinase-resistant penicillin 1
• Aspiration pneumonia (community-acquired): Penicillin G, or lincosamide, or penicillin/β-lactamase inhibitor combination 1

Route of Administration and Transition to Oral Therapy

• The oral route is recommended for non-severe pneumonia unless contraindications exist 1
• Patients initially treated with parenteral antibiotics should be switched to oral therapy when clinical improvement occurs and temperature has been normal for 24 hours, with no contraindication to oral route 1, 2
• The practice of switching from IV to oral fluoroquinolone after 5-7 days is gaining acceptance 1
• Review route of administration initially on the "post-take" round and then daily 1

Management of Treatment Failure

• If patients fail to improve after 48-72 hours, conduct a careful review by an experienced clinician of clinical history, examination, prescription chart, and all investigation results 1, 2
• Order further investigations: repeat chest radiograph, CRP, white cell count, and additional microbiological specimens 1, 2
• For non-severe pneumonia on amoxicillin monotherapy: add or substitute a macrolide 1, 2
• For non-severe pneumonia on combination therapy: consider changing to a fluoroquinolone with effective pneumococcal cover 1
• For severe pneumonia not responding to combination therapy: consider adding rifampicin 1, 2

Special Populations

Pregnancy

• For mild pneumonia in pregnancy, oral amoxicillin is first-line 2
• For severe pneumonia in pregnancy, use IV broad-spectrum β-lactamase stable antibiotic (co-amoxiclav, cefuroxime, or ceftriaxone) plus macrolide (clarithromycin or erythromycin) 2
• Fluoroquinolones should generally be avoided during pregnancy unless benefits outweigh risks 2
• If antifungal therapy is needed, amphotericin B is the treatment of choice as fluconazole and other azoles are teratogenic 2

Duration of Therapy

• Treatment duration should generally not exceed 8 days in a responding patient 1
• Uncomplicated S. pneumoniae pneumonia is typically treated for 7-10 days 1, 2
• Biomarkers, particularly procalcitonin (PCT), may guide shorter treatment duration 1

Critical Timing Considerations

• Antibiotic treatment should be initiated immediately after diagnosis of CAP 1
• In patients with CAP and sepsis, immediate administration is essential 1
• Antimicrobial treatment must be empirical initially and should follow an approach based on individual risk of mortality 1

Common Pitfalls and Caveats

• Do not delay antibiotic administration while awaiting culture results; empiric therapy should begin immediately 1, 2
• Avoid fluoroquinolones as first-line community agents to preserve their effectiveness and reduce resistance development 1
• Be aware that some Pseudomonas aeruginosa isolates may develop resistance rapidly during levofloxacin treatment 4
• Macrolides (azithromycin) can cause QT prolongation and torsades de pointes; use caution in patients with known QT prolongation, bradyarrhythmias, or those on QT-prolonging medications 5
• Clostridium difficile-associated diarrhea (CDAD) can occur with azithromycin and other antibiotics; consider this diagnosis in patients developing diarrhea during or after treatment 5
• Patients requiring tracheostomy or endotracheal intubation may have persistent tracheal colonization after clinical cure 1
• Relief of endobronchial obstruction and drainage of empyema fluid remain essential adjuncts to antibiotic therapy 1