What is the initial treatment for community-acquired pneumonia (CAP) in pediatric patients?

Community-Acquired Pneumonia in Pediatric Patients: Initial Treatment

For previously healthy, appropriately immunized children with mild to moderate community-acquired pneumonia, amoxicillin 90 mg/kg/day divided into 2 doses is the first-line treatment across all age groups from infancy through adolescence. 1

Age-Specific Treatment Algorithm

Preschool-Aged Children (Under 5 Years)

Critical Decision Point: Most preschool-aged children with CAP have viral infections and do not require antibiotics. 1

• Antimicrobial therapy is NOT routinely required for preschool-aged children with CAP because viral pathogens cause the majority of clinical disease. 1
• When bacterial pneumonia is suspected (high fever, focal consolidation, elevated inflammatory markers), use amoxicillin 90 mg/kg/day divided into 2 doses for 5-7 days. 1, 2
• This high-dose regimen provides adequate coverage against penicillin-resistant Streptococcus pneumoniae, the most important invasive bacterial pathogen. 1

For penicillin-allergic patients:

• Non-anaphylactic allergy: Use oral cephalosporins (cefpodoxime, cefuroxime, or cefprozil). 3
• Type I hypersensitivity/anaphylaxis: Use azithromycin or clarithromycin. 3

School-Aged Children and Adolescents (5 Years and Older)

Critical Decision Point: This age group has higher rates of atypical pathogens (Mycoplasma pneumoniae, Chlamydophila pneumoniae). 1

For typical bacterial pneumonia:

• Amoxicillin 90 mg/kg/day divided into 2 doses remains first-line therapy for S. pneumoniae. 1

For atypical pneumonia (gradual onset, prominent cough, minimal fever):

• Azithromycin 10 mg/kg on day 1 (maximum 500 mg), then 5 mg/kg daily on days 2-5 (maximum 250 mg) is the preferred macrolide. 4, 5
• Alternative macrolides include clarithromycin 15 mg/kg/day divided into 2 doses for 7-14 days (maximum 1 g/day). 4

When you cannot distinguish between typical and atypical pneumonia:

• Add a macrolide to amoxicillin for dual coverage of both typical and atypical pathogens. 4

Hospitalized Patients

Fully Immunized Children in Areas with Low Penicillin Resistance

• Ampicillin 150-200 mg/kg/day IV every 6 hours OR penicillin G 200,000-250,000 U/kg/day IV every 4-6 hours. 1
• This narrow-spectrum approach is appropriate when local epidemiology documents minimal high-level penicillin resistance. 1

Incompletely Immunized Children OR High Penicillin Resistance Areas OR Life-Threatening Infection

• Ceftriaxone 50-100 mg/kg/day IV every 12-24 hours OR cefotaxime 150 mg/kg/day IV every 8 hours. 1
• Third-generation cephalosporins are NOT inferior to vancomycin for current levels of pneumococcal resistance in North America. 1

When Atypical Pathogens Are Suspected in Hospitalized Children

• Add a macrolide (azithromycin or clarithromycin) to β-lactam therapy. 1
• Obtain diagnostic testing for M. pneumoniae if available in a clinically relevant timeframe. 1

When Community-Acquired MRSA Is Suspected

Clinical indicators: Severe necrotizing pneumonia, empyema, recent influenza infection, or local MRSA prevalence. 1

• Add vancomycin 40-60 mg/kg/day IV every 6-8 hours OR clindamycin 40 mg/kg/day IV every 6-8 hours (based on local susceptibility). 1, 3

Influenza-Associated Pneumonia

• Administer antiviral therapy immediately for moderate to severe CAP during influenza season, particularly with clinical worsening. 1
• Do NOT delay treatment waiting for influenza test confirmation—negative rapid tests do not exclude influenza. 1
• Treatment after 48 hours may still benefit those with severe disease. 1

Treatment Duration and Monitoring

• Standard duration: 5-7 days for uncomplicated CAP. 2, 3
• Expect clinical improvement within 48-72 hours: decreased fever, improved respiratory rate, reduced work of breathing. 1, 3
• If no improvement or deterioration at 48-72 hours: Obtain repeat chest radiograph, consider resistant organisms, evaluate for complications (parapneumonic effusion), reassess diagnosis. 1, 3, 4

Critical Pitfalls to Avoid

Do not use macrolides as monotherapy in children under 5 years—they provide inadequate coverage for S. pneumoniae. 3

Avoid fluoroquinolones (levofloxacin) in children who have not reached growth maturity due to cartilage development concerns. 4

Avoid doxycycline in children ≤7 years due to tooth discoloration risk. 4

Do not routinely obtain chest radiographs for mild outpatient CAP—reserve imaging for suspected hypoxemia, significant respiratory distress, or failed initial therapy. 3

Switch from IV to oral antibiotics when the child is afebrile for 24 hours, shows improved respiratory status, and tolerates oral intake—prolonged IV therapy is unnecessary. 3