First-Line Outpatient Treatment for Community-Acquired Pneumonia in a 14-Year-Old
Oral amoxicillin 90 mg/kg/day divided into 2 doses (maximum 4 g/day) is the first-line treatment for a previously healthy, fully immunized 14-year-old with community-acquired pneumonia. 1
Primary Antibiotic Selection
High-dose amoxicillin (90 mg/kg/day in 2 divided doses, maximum 4 g/day) provides optimal coverage against Streptococcus pneumoniae, the most important invasive bacterial pathogen in this age group. 1
For a 14-year-old, this typically translates to 2000 mg twice daily (using 2000 mg tablets) for most adolescents. 1
The high dosing is critical because it overcomes intermediate penicillin resistance in pneumococcal strains. 1
When to Add Macrolide Coverage
Consider adding a macrolide antibiotic if atypical pathogens (Mycoplasma pneumoniae, Chlamydophila pneumoniae) are suspected, as these become increasingly common in school-aged children and adolescents. 1
Azithromycin is the preferred macrolide: 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg (maximum 250 mg) once daily on days 2-5. 1, 2
Alternative macrolides include clarithromycin 15 mg/kg/day in 2 doses (maximum 1 g/day) or erythromycin. 1
For adolescents ≥8 years old, doxycycline is an acceptable alternative for atypical coverage. 1
The 2011 IDSA/PIDS guidelines note that for children ≥5 years without clear clinical, laboratory, or radiographic distinction between typical bacterial and atypical CAP, a macrolide can be added to β-lactam therapy for empiric coverage. 1
Treatment Duration
A 5-day course of antibiotics is recommended for uncomplicated community-acquired pneumonia in children demonstrating early clinical improvement. 3
The SCOUT-CAP trial demonstrated that 5 days of therapy was superior to 10 days when considering clinical response, adverse effects, and antibiotic resistance—with 69% probability of a more desirable outcome with the shorter course. 3
Children should demonstrate clinical improvement within 48-72 hours, including decreased fever, improved respiratory rate, and reduced respiratory distress. 1
Alternative Regimens
For penicillin-allergic patients (non-anaphylactic):
- Amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component in 2 doses, maximum 4 g/day) is an acceptable alternative. 1
For Type I hypersensitivity (anaphylaxis) to penicillin:
- Macrolide monotherapy with azithromycin or clarithromycin can be used, though this provides suboptimal pneumococcal coverage. 1
Critical Monitoring Parameters
Reassess the patient at 48-72 hours after initiating therapy to evaluate for:
- Resolution or significant improvement of fever 1
- Decreased respiratory rate and work of breathing 1
- Improved oral intake and overall clinical appearance 1
If no improvement or clinical deterioration occurs within 48-72 hours, further investigation is mandatory, including:
- Consideration of resistant organisms 1
- Evaluation for complications such as parapneumonic effusion 1
- Reassessment of antibiotic choice and dosing 1
- Possible need for hospitalization 1
Common Pitfalls to Avoid
Do not use macrolide monotherapy as first-line treatment in this age group, as it provides inadequate coverage for S. pneumoniae, which remains the most important invasive pathogen. 1
Do not underdose amoxicillin—the 90 mg/kg/day dosing (not the standard 40-50 mg/kg/day) is essential for overcoming pneumococcal resistance. 1, 4
Do not routinely obtain chest radiographs in well-appearing outpatients, as clinical diagnosis is sufficient and imaging leads to overdiagnosis and unnecessary antibiotic use. 5
Do not obtain blood cultures in non-toxic, fully immunized outpatients, as the yield is extremely low. 5
Special Considerations for Adolescents
Atypical pathogens (M. pneumoniae) are more common in school-aged children and adolescents than in younger children, which is why empiric macrolide addition should be strongly considered in this age group. 1
Recent Italian consensus (2024) recommends considering macrolide addition in children >5 years if symptoms persist after 48 hours of amoxicillin therapy and clinical condition remains stable. 4
The evidence supporting shorter antibiotic courses (5 days vs 10 days) is particularly strong, with reduced antibiotic resistance genes detected in oropharyngeal flora with the shorter course. 3