Bactrim (Trimethoprim-Sulfamethoxazole) for Pediatric Community-Acquired Pneumonia
Bactrim is not recommended as first-line therapy for community-acquired pneumonia in children and does not appear in any current major pediatric pneumonia treatment guidelines. 1
Why Bactrim Is Not Recommended
The most authoritative pediatric pneumonia guidelines from the Pediatric Infectious Diseases Society and Infectious Diseases Society of America (2011) do not include trimethoprim-sulfamethoxazole (Bactrim) in their empiric treatment algorithms for any age group or severity level. 1
Amoxicillin is the evidence-based first-line antibiotic for bacterial pneumonia in children, providing appropriate coverage for Streptococcus pneumoniae, the most prominent invasive bacterial pathogen causing pediatric CAP. 1, 2, 3
Age-Specific First-Line Recommendations
Children Under 5 Years
- Outpatient: Oral amoxicillin 90 mg/kg/day divided in 2 doses 1, 2, 3
- Inpatient (fully immunized): Ampicillin or penicillin G if local penicillin resistance is minimal 1
- Inpatient (not fully immunized or high resistance areas): Ceftriaxone or cefotaxime 1
Children 5 Years and Older
- Outpatient: Oral amoxicillin 90 mg/kg/day (maximum 4 g/day) for bacterial pneumonia 1, 2
- Add macrolide (azithromycin, clarithromycin, or erythromycin) if atypical pathogens (Mycoplasma pneumoniae) are suspected 1, 2
Historical Context on Bactrim
One older study from 1991 compared trimethoprim/rifampin with ampicillin in 60 children with mild CAP and found ampicillin superior, with fever persisting 7.0 days in the TMP group versus 5.2 days in the ampicillin group, and 5 clinical/microbiologic failures in the TMP group versus none with ampicillin. 4 This supports avoiding trimethoprim-based regimens for pediatric pneumonia.
Critical Pitfalls to Avoid
- Do not use Bactrim as empiric therapy for pediatric CAP, as it lacks adequate coverage for S. pneumoniae, the primary pathogen 1
- Do not delay appropriate beta-lactam therapy in favor of alternative agents without clear contraindications 1, 3
- For children with true penicillin allergy, appropriate alternatives include levofloxacin, linezolid, or clindamycin (if susceptible), but not Bactrim 1
When Antibiotics May Not Be Needed
Antimicrobial therapy is not routinely required for preschool-aged children with CAP, as viral pathogens cause the majority of clinical disease in this age group. 1, 3 Young children with mild lower respiratory tract infection symptoms may not need antibiotics at all. 1, 2