For acute sinusitis in adults and children, which antibiotic is considered first-line according to the source?

• A. Amoxicillin-clavulanate
• B. Amoxicillin
• C. Azithromycin
• D. Doxycycline

Answer: (A)

Acute sinusitis treatment centers on reliably covering the common bacterial culprits, including beta-lactamase–producing strains. Amoxicillin-clavulanate provides strong activity against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, including beta-lactamase–producing organisms, which is why it’s the preferred first-line therapy for both adults and children. The clavulanate component blocks the beta-lactamase enzymes, allowing the amoxicillin to work where it otherwise wouldn’t. Using a high-dose regimen helps ensure adequate drug levels to overcome potential resistance and improve cure rates. Alternatives like doxycycline or macrolides have higher resistance rates and narrower coverage, so they’re not first-line in typical cases.