Amoxicillin Dosage for Otitis Media in a 16.4 kg Child
For a 16.4 kg child with otitis media, the recommended dosage of amoxicillin is 80-90 mg/kg/day divided into 2-3 doses for 10 days, which equals approximately 1,300-1,480 mg per day or 430-490 mg per dose if given three times daily. 1
First-Line Treatment Selection
High-dose amoxicillin is the current first-line recommendation for acute otitis media (AOM) according to the American Academy of Pediatrics (AAP) and American Academy of Family Physicians (AAFP) guidelines. This recommendation is based on:
- Increasing prevalence of drug-resistant Streptococcus pneumoniae
- Need for adequate coverage against common pathogens including H. influenzae and M. catarrhalis
- Excellent middle ear fluid penetration of amoxicillin
Specific Dosing Calculation
For this 16.4 kg child:
- At 80 mg/kg/day: 16.4 kg × 80 mg/kg = 1,312 mg/day
- At 90 mg/kg/day: 16.4 kg × 90 mg/kg = 1,476 mg/day
- Divided into 3 doses: approximately 437-492 mg per dose
Treatment Duration
- For a child with otitis media, the recommended duration of treatment is:
- 10 days for children under 2 years of age
- 7-10 days for children 2 years and older depending on severity 1
Alternative Options
If the child has a penicillin allergy or treatment failure occurs:
For non-Type I allergy:
- Cefdinir (14 mg/kg/day in 1-2 doses)
- Cefuroxime (30 mg/kg/day in 2 divided doses)
- Cefpodoxime (10 mg/kg/day in 2 divided doses) 1
For Type I/severe allergy:
- Clindamycin (30-40 mg/kg/day in 3 divided doses)
- Ceftriaxone (50 mg/kg IM or IV daily for 3 days) if not allergic to cephalosporins 1
Treatment Failure Considerations
If no improvement is seen after 48-72 hours of therapy:
- Consider switching to amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component)
- Beta-lactamase-producing H. influenzae is the most common cause of treatment failure with high-dose amoxicillin 2
Important Clinical Pearls
Monitor for side effects: Diarrhea is the most common side effect of amoxicillin. Consider probiotic supplementation taken 2 hours before or after antibiotics to reduce gastrointestinal side effects.
Pain management: Always assess for pain and provide appropriate analgesia (acetaminophen or ibuprofen) if pain is present.
Follow-up: Reassess the child after 48-72 hours of therapy to evaluate treatment response.
Common pitfall: Using standard-dose amoxicillin (40-45 mg/kg/day) is inadequate for areas with high prevalence of resistant S. pneumoniae. The higher dose (80-90 mg/kg/day) is necessary to achieve adequate middle ear fluid concentrations 3.
Special consideration: If the child has tympanostomy tubes with visible drainage, topical antibiotic drops would be preferred over oral antibiotics 1.