What is the first-line antibiotic for acute bacterial rhinosinusitis in adults without penicillin allergy?

What is the first-line antibiotic for acute bacterial rhinosinusitis in adults without penicillin allergy?

• A. Amoxicillin-clavulanate (Augmentin)
• B. Doxycycline
• C. Azithromycin
• D. Cefdinir

Answer: (A)

High-dose amoxicillin-clavulanate is chosen first because it reliably covers the usual bacteria that cause acute bacterial rhinosinusitis and counters beta-lactamase–producing strains. The clavulanate component blocks that resistance mechanism, expanding activity against Haemophilus influenzae and Moraxella catarrhalis, as well as susceptible Streptococcus pneumoniae. This makes it more effective in the typical adult patient without penicillin allergy than amoxicillin alone or many alternatives. Doxycycline can be used if penicillin allergy is present, but isn’t preferred in nonallergic patients due to variability in coverage and resistance. Azithromycin has higher resistance and weaker pneumococcal activity, and cefdinir has less robust evidence guiding its use as first-line.

High-dose amoxicillin-clavulanate is chosen first because it reliably covers the usual bacteria that cause acute bacterial rhinosinusitis and counters beta-lactamase–producing strains. The clavulanate component blocks that resistance mechanism, expanding activity against Haemophilus influenzae and Moraxella catarrhalis, as well as susceptible Streptococcus pneumoniae. This makes it more effective in the typical adult patient without penicillin allergy than amoxicillin alone or many alternatives. Doxycycline can be used if penicillin allergy is present, but isn’t preferred in nonallergic patients due to variability in coverage and resistance. Azithromycin has higher resistance and weaker pneumococcal activity, and cefdinir has less robust evidence guiding its use as first-line.