Treatment Differences Between Adult and Pediatric Community-Acquired Pneumonia
The fundamental differences in treating adult versus pediatric pneumonia center on first-line antibiotic selection, dosing strategies, pathogen considerations by age, and treatment duration, with children under 5 years receiving amoxicillin monotherapy while adults typically require combination therapy with a macrolide.
First-Line Antibiotic Selection
Pediatric Patients
For children under 5 years with presumed bacterial pneumonia, amoxicillin monotherapy (90 mg/kg/day in 2 doses) is the preferred first-line treatment 1. This differs fundamentally from adult management because:
- Young children have lower rates of atypical pathogens (Mycoplasma, Chlamydia) 1
- Streptococcus pneumoniae remains the predominant bacterial pathogen in this age group 1
- Amoxicillin provides adequate coverage without unnecessary broad-spectrum exposure 1
For children 5 years and older, macrolide antibiotics may be used as first-line empirical treatment because Mycoplasma pneumoniae becomes more prevalent in this age group 1. Alternatively, amoxicillin can be used with a macrolide added if atypical pneumonia cannot be distinguished from bacterial CAP 1.
Adult Patients
Adults in the community setting should receive amoxicillin at higher doses than previously recommended, but macrolides (erythromycin or clarithromycin) are offered as alternatives 1. This represents a key difference from pediatric management where macrolides are reserved for specific indications.
For hospitalized adults with non-severe CAP, combined oral therapy with amoxicillin plus a macrolide is preferred 1. This combination approach reflects:
- Higher prevalence of atypical pathogens in adults 2
- Need for broader empiric coverage in hospitalized patients 1
- Evidence supporting combination therapy for improved outcomes 3
Severe Disease Management
Pediatric Inpatients
Fully immunized children with minimal local penicillin resistance should receive ampicillin or penicillin G as first-line therapy 1. Alternatives include ceftriaxone or cefotaxime, with vancomycin or clindamycin added only if CA-MRSA is suspected 1.
For children not fully immunized or in areas with significant penicillin resistance, ceftriaxone or cefotaxime should be used instead 1.
Adult Inpatients with Severe CAP
Adults with severe pneumonia require immediate parenteral combination therapy with a broad-spectrum β-lactamase stable antibiotic (co-amoxiclav or second/third generation cephalosporin) plus a macrolide 1. This aggressive combination approach is not routinely used in pediatric severe CAP unless specific pathogens are suspected 1.
Pathogen-Specific Considerations
Atypical Pathogens
In children, azithromycin (10 mg/kg on day 1, then 5 mg/kg/day for days 2-5) is preferred for Mycoplasma or Chlamydia pneumonia 1. Alternatives include clarithromycin or erythromycin, with doxycycline reserved for children over 7 years old 1.
Adults with atypical pneumonia receive similar macrolide regimens, but fluoroquinolones with enhanced pneumococcal activity (levofloxacin) represent an important alternative not routinely used in children 1. Fluoroquinolones in pediatrics are reserved for specific circumstances when children cannot tolerate macrolides or have reached skeletal maturity 1.
Staphylococcus aureus
When S. aureus is suspected in children, either a macrolide alone or combination flucloxacillin with amoxicillin is appropriate 1. CA-MRSA infections may require longer treatment courses than S. pneumoniae in both populations 1.
Treatment Duration
Pediatric Duration
Treatment courses of 10 days have been best studied in children, though shorter courses may be equally effective for mild disease managed outpatient 1. Specific pathogen considerations:
- Standard bacterial pneumonia: 10 days 1
- CA-MRSA infections: longer than 10 days 1
- Azithromycin courses: 3-5 days have shown equivalent efficacy 1
Adult Duration
For adults managed in the community and most hospitalized with non-severe pneumonia, 7 days of appropriate antibiotics is recommended 1. This represents a shorter standard duration than pediatric recommendations 4.
Severe adult pneumonia requires 10 days of treatment, extended to 14-21 days for Legionella, staphylococcal, or Gram-negative enteric bacilli 1.
Route of Administration
Most hospitalized adults with non-severe pneumonia can be adequately treated with oral antibiotics 1. Parenteral therapy should be switched to oral once clinical improvement occurs and temperature normalizes for 24 hours 1.
In children, parenteral administration is reserved for severely ill patients where rapid high lung concentrations are needed, or when oral absorption is compromised 1. One study showed no difference between single-dose IM penicillin plus oral amoxicillin versus standard oral therapy in emergency department pediatric pneumonia 1.
Critical Pitfalls
Avoid fluoroquinolones as first-line agents in children - they should only be used when macrolides cannot be tolerated or in adolescents with skeletal maturity 1. In adults, fluoroquinolones are not recommended for first-line community use but provide useful alternatives in hospitalized patients 1.
Do not use amoxicillin monotherapy in hospitalized adults - combination with a macrolide is preferred to cover atypical pathogens 1. This contrasts with pediatric management where amoxicillin monotherapy remains appropriate for young children 1.
Reassess clinical response at 48-72 hours in both populations - failure to improve warrants investigation for complications, resistant organisms, or alternative diagnoses 1.