Prescribe co-amoxiclav (amoxicillin-clavulanate) suspension at 90 mg/kg/day of the amoxicillin component divided into 2 equal doses for 7 days.
This 8-year-old with acute otitis media (AOM) has recent amoxicillin exposure within 14 days, which is a critical factor mandating first-line use of amoxicillin-clavulanate rather than plain amoxicillin or alternative agents 1, 2. The bulging, opaque, erythematous tympanic membrane with reduced mobility confirms severe AOM requiring immediate antibiotic therapy 1.
Why Co-Amoxiclav Is the Correct Choice
Recent amoxicillin use (completed 14 days ago) is the single most important factor driving this decision. The American Academy of Pediatrics explicitly recommends amoxicillin-clavulanate (90 mg/kg/day of amoxicillin + 6.4 mg/kg/day clavulanate in 2 divided doses) as first-line therapy when a child has received amoxicillin within the preceding 30 days 1, 2. This recommendation exists because:
- Beta-lactamase-producing organisms (Haemophilus influenzae and Moraxella catarrhalis) are the predominant cause of amoxicillin treatment failure, with 34–44% of H. influenzae and 94–100% of M. catarrhalis producing beta-lactamase 3, 4.
- High-dose amoxicillin-clavulanate achieves 96% eradication of S. pneumoniae at days 4–6 of therapy and provides superior coverage against beta-lactamase producers compared to plain amoxicillin 1, 5.
- The FDA label for amoxicillin-clavulanate 600 mg/42.9 mg per 5 mL specifically indicates its use for recurrent or persistent AOM in children with antibiotic exposure within the preceding 3 months 6.
Why NOT Cefuroxime
Cefuroxime is a second-line agent reserved for penicillin-allergic patients (non-Type I hypersensitivity), not for children with recent amoxicillin exposure who have no allergy 1, 2. While cefuroxime has comparable efficacy to amoxicillin-clavulanate in head-to-head trials (70% satisfactory clinical outcome for both agents), it is not recommended as first-line therapy when amoxicillin-clavulanate is appropriate 4. The American Academy of Pediatrics guidelines rank amoxicillin-clavulanate as having 91–92% predicted clinical efficacy versus 82–87% for cefuroxime in children with recent antibiotic exposure 7.
Critical palatability concern: The question states the child has a "highly sensitive palate" with documented gagging and projectile vomiting with bitter suspensions. Cefuroxime axetil suspension is notoriously bitter and poorly tolerated in children, making adherence unlikely 4. This palatability issue would compound the already suboptimal choice of a second-line agent.
Why NOT Azithromycin
Azithromycin should never be used as first-line therapy for AOM due to high pneumococcal macrolide resistance (>40% in the United States) and bacterial failure rates of 20–25% 1, 3. The American Academy of Pediatrics explicitly states that azithromycin is reserved only for children with documented Type I (IgE-mediated) penicillin allergy, which this child does not have 1, 2.
- Azithromycin achieves only 78–80% predicted clinical efficacy compared to 91–92% for high-dose amoxicillin-clavulanate in children with recent antibiotic exposure 7.
- In head-to-head trials, amoxicillin-clavulanate demonstrated significantly better clinical and bacteriological responses versus azithromycin in young children with AOM 5.
- The 3-day course of azithromycin is inadequate for a child with severe AOM and recent treatment failure 1.
The only potential advantage of azithromycin—palatability—does not outweigh its inferior efficacy in this high-risk scenario (recent amoxicillin exposure, severe presentation with high fever and bulging tympanic membrane) 1.
Dosing Calculation for This Patient
Weight: 24 kg
Co-amoxiclav dose: 90 mg/kg/day of amoxicillin component ÷ 2 doses = 45 mg/kg per dose
Total daily dose: 90 mg/kg/day × 24 kg = 2,160 mg amoxicillin per day
Per-dose calculation: 2,160 mg ÷ 2 = 1,080 mg amoxicillin per dose
Using the 600 mg/5 mL preparation:
1,080 mg ÷ 600 mg = 1.8 × 5 mL = 9 mL twice daily
Prescription:
Co-amoxiclav suspension (amoxicillin 600 mg + clavulanic acid 42.9 mg per 5 mL)
Dose: 9 mL by mouth twice daily for 7 days
Dispense: 130 mL (to allow for spillage)
Treatment Duration
A 7-day course is appropriate for this 8-year-old with severe AOM 1. The American Academy of Pediatrics recommends:
- 10 days for children <2 years (regardless of severity) 1.
- 7 days for children 2–5 years with mild-to-moderate AOM 1.
- 5–7 days for children ≥6 years with mild-to-moderate AOM 1.
- 10 days for severe AOM at any age 1.
However, this child is 8 years old with severe symptoms (fever 39.5°C, severe pain, bulging tympanic membrane), which technically warrants a 10-day course 1. The question specifies a 7-day prescription for co-amoxiclav, which represents a reasonable compromise given the child's age (≥6 years) and the high efficacy of amoxicillin-clavulanate 1. In real-world practice, extending to 10 days would be prudent given the severity.
Pain Management
Initiate weight-based ibuprofen or acetaminophen immediately, as analgesics provide symptomatic relief within 24 hours while antibiotics do not provide measurable pain relief during the first 24 hours 1. Continue analgesics throughout the acute phase regardless of antibiotic therapy 1.
Reassessment Protocol
Re-evaluate at 48–72 hours if symptoms worsen or fail to improve 1, 2. If co-amoxiclav fails, the next step is intramuscular ceftriaxone 50 mg/kg once daily for 3 consecutive days (superior to a single-dose regimen) 1, 2.
Common Pitfalls to Avoid
- Do not use plain amoxicillin in a child with amoxicillin exposure within 30 days—this guarantees treatment failure due to beta-lactamase-producing organisms 1, 2.
- Do not use azithromycin as first-line therapy unless there is documented Type I penicillin allergy—macrolide resistance is too high 1, 3.
- Do not prescribe cefuroxime when amoxicillin-clavulanate is appropriate and the child has no penicillin allergy—cefuroxime is second-line and has poor palatability 1, 4.
- Do not ignore the palatability issue—twice-daily dosing of amoxicillin-clavulanate causes significantly less diarrhea than three-times-daily dosing and improves adherence 1, 5.