Pneumonia Treatment
For non-severe community-acquired pneumonia in outpatients, amoxicillin monotherapy is the preferred first-line treatment, with a 5-7 day course being sufficient for most cases. 1
Outpatient Treatment Algorithm
First-Line Therapy for Previously Healthy Patients
- Amoxicillin monotherapy is the recommended initial agent for patients without comorbidities who can be managed in the community 1
- Treatment duration should be 7 days for uncomplicated cases 1
- Oral therapy is appropriate from the beginning for ambulatory patients 1
Penicillin-Allergic Patients
- A macrolide (e.g., azithromycin) is recommended as the alternative 1
- Be aware that azithromycin can cause serious allergic reactions including anaphylaxis and Stevens-Johnson syndrome, though these are rare 2
- QT prolongation is a significant risk with azithromycin, particularly in elderly patients, those with cardiac conditions, or those on other QT-prolonging medications 2
Patients with Comorbidities or Recent Antibiotic Use
- Combination therapy with a beta-lactam plus a macrolide is recommended 1, 3
- Alternatively, respiratory fluoroquinolone monotherapy (levofloxacin or moxifloxacin) can be used 3
- Fluoroquinolones achieve high lung penetration and demonstrate >90% clinical success rates against S. pneumoniae 3
- Levofloxacin is effective against macrolide-resistant S. pneumoniae 3
Inpatient Treatment for Severe Pneumonia
Immediate Management
- Immediate parenteral antibiotic administration is required for severe cases 1
- Intravenous combination of a broad-spectrum β-lactamase stable antibiotic plus a macrolide is the preferred regimen 1, 4
- Treatment duration should be 10-14 days for severe cases 1
Transition to Oral Therapy
- Switch from IV to oral therapy when the patient is hemodynamically stable and clinically improving 1
- Patient should be afebrile for 48-72 hours before antibiotic discontinuation 1
- Minimum treatment duration should be 5 days 1
Monitoring Treatment Response
Clinical Parameters to Track
- Monitor body temperature, respiratory parameters, and hemodynamic stability 1
- Measure C-reactive protein on days 1 and 3-4, especially in patients with unfavorable clinical parameters 1
When Initial Therapy Fails
- If no response to amoxicillin monotherapy, add a macrolide to cover atypical pathogens (Mycoplasma, Chlamydia, Legionella) 4
- Review antibiotic therapy and adjust based on culture results 4
- Consider extending treatment to 14-21 days for Legionella, staphylococcal, or gram-negative enteric bacilli pneumonia 4
- For suspected MRSA, use vancomycin or linezolid 4
Critical Pitfalls to Avoid
Inappropriate Patient Selection for Oral Therapy
- Do not use oral therapy alone for patients with moderate-to-severe illness, cystic fibrosis, nosocomial infections, suspected bacteremia, hospitalization requirements, elderly/debilitated status, or immunodeficiency 2
- Azithromycin specifically should not be used in these high-risk populations 2
Delayed Treatment Initiation
- Delay in appropriate antibiotic therapy is associated with increased mortality 4
- Start empiric therapy immediately while awaiting culture results 1
Overlooking Complications
- Monitor for C. difficile-associated diarrhea, particularly with broad-spectrum antibiotics 4, 2
- Consider non-infectious causes of persistent symptoms (heart failure, atelectasis, pulmonary embolism) 4
- Failure to recognize extrapulmonary infection can contribute to treatment failure 4
Drug-Specific Warnings
- Azithromycin carries risks of hepatotoxicity (discontinue immediately if hepatitis signs occur) 2
- QT prolongation with macrolides can be fatal in at-risk patients 2
- Levofloxacin should be used cautiously in patients with known QT prolongation or electrolyte abnormalities 5
Follow-Up Care
- Arrange clinical review at 6 weeks for all patients 4
- Obtain chest radiograph for persistent symptoms, especially in those at higher risk of underlying malignancy 4