For outpatient treatment of community-acquired pneumonia in adults without significant comorbidity, which is an acceptable first-line option?

• A. Macrolide
• B. Amoxicillin
• C. Ceftriaxone
• D. Vancomycin

Answer: (A)

Outpatient CAP in healthy adults is most effectively treated with an agent that covers both typical bacteria like Streptococcus pneumoniae and atypical pathogens such as Mycoplasma and Chlamydophila. A macrolide fits this need well, offering good activity against these organisms and convenient oral dosing, which makes it a solid first-line option for non-severe disease managed as an outpatient.

Amoxicillin concentrates on pneumococcus but lacks reliable atypical coverage, so it may miss common atypical causes of CAP. Ceftriaxone and vancomycin are typically reserved for inpatient care or more severe illness and MRSA/polymicrobial scenarios; they’re not appropriate first-line choices for outpatient management.