Management of Pneumonia
Initial Assessment and Severity Stratification
Use CURB-65 or similar severity scoring tools to determine treatment setting and guide antibiotic selection 1. Obtain chest radiography for all suspected pneumonia cases 1. For hospitalized patients, collect blood cultures, sputum for Gram stain and culture, complete blood count, renal and liver function tests, and oxygen saturation before initiating antibiotics 1.
Antibiotic Selection by Setting and Severity
Outpatient/Community Management (Non-Severe CAP)
For previously healthy outpatients, initiate treatment with a macrolide (azithromycin or clarithromycin), doxycycline, or a respiratory fluoroquinolone 1. Amoxicillin monotherapy is the preferred agent for patients managed in the community 2. For penicillin-allergic patients, use a respiratory fluoroquinolone or macrolide 1, 2.
- Treat for 7 days in uncomplicated community-managed pneumonia 2
- Oral therapy is appropriate from the beginning for ambulatory patients 2
Hospitalized Patients (Non-ICU, Non-Severe)
First-line therapy should be a β-lactam (amoxicillin, ampicillin, or cefuroxime) plus a macrolide (clarithromycin or erythromycin) 1, 2. The oral route is recommended for non-severe pneumonia admitted to hospital when there are no contraindications 3, 1.
- Combined oral therapy with amoxicillin and a macrolide is preferred for patients requiring hospital admission 3
- When oral treatment is contraindicated, use intravenous ampicillin or benzylpenicillin together with erythromycin or clarithromycin 3
- For penicillin-allergic patients, a respiratory fluoroquinolone is an alternative 1
Severe CAP (ICU Patients)
Immediate parenteral antibiotic administration is required with an intravenous combination of a broad-spectrum β-lactamase stable antibiotic (co-amoxiclav, cefuroxime, cefotaxime, or ceftriaxone) plus a macrolide (clarithromycin or erythromycin) 3, 2. For ICU patients, the combination should be a β-lactam plus either azithromycin or a fluoroquinolone 1.
- Alternative regimen: fluoroquinolone with enhanced pneumococcal activity (levofloxacin) plus intravenous benzylpenicillin for patients intolerant of β-lactams or macrolides 3
- Treatment duration should be 10 days for severe microbiologically undefined pneumonia 3
- Extend to 14-21 days when Legionella, Staphylococcus, or Gram-negative enteric bacilli are suspected or confirmed 3
Route of Administration and Transition
Switch from intravenous to oral therapy when patients are hemodynamically stable, improving clinically, able to ingest medications, and have a normally functioning gastrointestinal tract 1, 2. For patients admitted through the emergency department, administer the first antibiotic dose while still in the ED 1.
Treatment Duration
Treat for a minimum of 5 days, ensuring the patient is afebrile for 48-72 hours and has no more than one CAP-associated sign of clinical instability before stopping antibiotics 1, 2. The standard duration is 7 days for uncomplicated pneumonia 1, 2.
Monitoring Response to Treatment
Review clinical response daily, including temperature, respiratory parameters, and hemodynamic status 1, 2. Measure C-reactive protein on days 1 and 3-4, especially in patients with unfavorable clinical parameters 2.
Management of Treatment Failure
For patients failing to improve, conduct a careful review by an experienced clinician of clinical history, examination, prescription chart, and all investigation results 3. Obtain repeat chest radiograph, CRP, white cell count, and additional microbiological specimens 3, 1.
When changing empirical therapy:
- For non-severe pneumonia on amoxicillin monotherapy: substitute or add a macrolide 3
- For non-severe pneumonia on combination therapy: consider switching to a fluoroquinolone with effective pneumococcal cover 3
- For severe pneumonia not responding to combination therapy: consider adding rifampicin 3
Special Considerations and Contraindications
Azithromycin should not be used in patients with pneumonia judged inappropriate for oral therapy due to moderate-to-severe illness, including those with cystic fibrosis, nosocomial infections, known/suspected bacteremia, requiring hospitalization, elderly/debilitated patients, or those with immunodeficiency or functional asplenia 4.
Exercise caution with macrolides (particularly azithromycin) in patients with prolonged QT interval, history of torsades de pointes, congenital long QT syndrome, bradyarrhythmias, uncompensated heart failure, uncorrected electrolyte abnormalities, or those on QT-prolonging medications 4. Elderly patients are more susceptible to QT prolongation effects 4.
Prevention
Recommend influenza vaccination for high-risk groups including those with chronic lung, heart, renal, and liver disease, diabetes mellitus, immunosuppression, and adults over 65 years 1, 2. Consider pneumococcal vaccination for those at increased risk of pneumococcal infection 1, 2.