An 18-month-old girl with fever to 38.9°C and ear pain has just completed a 10-day course of amoxicillin four days ago for a right ear infection. What is the most appropriate antibiotic regimen for this episode?

• A. 7-day course of amoxicillin, 45 mg/kg/day
• B. 10-day course of amoxicillin-clavulanic acid, 90 mg/kg/day
• C. 5-day course of azithromycin
• D. 14-day course of cefdinir

Answer: (B)

When a child with acute otitis media has recently completed an antibiotic course, especially amoxicillin, and returns with fever and ear pain, the best approach is to switch to high-dose amoxicillin-clavulanic acid to cover organisms that produce beta-lactamase. The prior use of amoxicillin within the past month raises the chance that the common bacteria causing AOM (like Haemophilus influenzae and Moraxella catarrhalis) are resistant due to beta-lactamase, so adding clavulanate helps inhibit that resistance. Using a high-dose amoxicillin component (about 90 mg/kg/day, typically divided into two doses) ensures adequate drug levels to tackle these pathogens, and a 10-day course is appropriate for a young child with significant symptoms to promote full resolution.

This option is preferable to repeating plain amoxicillin, which would be less effective after recent exposure. Azithromycin is less reliable for AOM due to variable activity against the usual pathogens and higher resistance rates. Cefdinir alone may not reliably cover beta-lactamase–producing organisms and is not the preferred step after amoxicillin failure.