In a 5-year-old child with fever, productive cough, and signs suggestive of pneumonia, what is the most appropriate first-line antibiotic?

• A. Azithromycin
• B. Cefaclor
• C. Amoxicillin
• D. Doxycycline

Answer: (C)

For suspected bacterial pneumonia in a child, you want a narrow-spectrum antibiotic that targets the most likely pathogens in that age group. Amoxicillin fits this role because Streptococcus pneumoniae and Haemophilus influenzae are the common causes in a 5-year-old, and amoxicillin has strong activity against these bacteria, is safe and well tolerated, and can be given orally. Using a high-dose regimen improves coverage against penicillin-susceptible pneumococci and helps ensure effective treatment in the community setting, while avoiding unnecessary broad-spectrum coverage.

Azithromycin would be more appropriate if an atypical pathogen were suspected or if there were a penicillin allergy, but atypicals are less common in this age, and macrolides are not the first choice for typical pneumococcal pneumonia. Doxycycline is generally avoided in young children due to effects on teeth and bone development. Cefaclor is broader than necessary and may have more side effects and resistance concerns without providing a clear advantage over high-dose amoxicillin for typical CAP in a 5-year-old.