Amoxicillin 250mg/5ml Suspension for 90 mg/kg/day BID Dosing in a 14 kg Patient
Yes, you can use 250mg/5ml amoxicillin suspension to deliver 90 mg/kg/day BID to a 14 kg patient, and this is the recommended high-dose regimen for acute otitis media and other resistant infections in children. 1, 2
Dose Calculation
For a 14 kg patient receiving 90 mg/kg/day divided BID:
- Total daily dose: 90 mg/kg/day × 14 kg = 1,260 mg/day 2
- Per-dose amount: 1,260 mg ÷ 2 doses = 630 mg per dose 2
- Volume per dose using 250mg/5ml: 630 mg ÷ 50 mg/ml = 12.6 ml per dose 3
This dosing is practical and falls well within the maximum pediatric amoxicillin dose of 4,000 mg/day. 4
Clinical Rationale for High-Dose Therapy
The American Academy of Pediatrics specifically recommends 80-90 mg/kg/day divided BID for acute otitis media in children to overcome drug-resistant Streptococcus pneumoniae. 1, 2
High-dose amoxicillin (80-90 mg/kg/day) is indicated when: 2, 5
- Treating acute otitis media in areas with penicillin-resistant S. pneumoniae prevalence >10% 2
- The child attends daycare 5
- Recent antibiotic exposure within the past 30 days 5
- Concurrent conjunctivitis is present 5
- Age less than 2 years 4
Pharmacokinetic Support
Research demonstrates that standard dosing (40 mg/kg/day) produces inadequate middle ear fluid concentrations against resistant organisms, particularly during viral coinfection. 6 Studies show that 75-90 mg/kg/day achieves therapeutic concentrations necessary to eradicate resistant S. pneumoniae. 6
The BID dosing schedule (rather than TID) improves compliance while maintaining adequate plasma concentrations above the MIC for >50% of the dosing interval. 7
Practical Administration
- Give 12.6 ml of the 250mg/5ml suspension every 12 hours 3
- Administer at the start of meals to minimize gastrointestinal intolerance 3
- Continue treatment for minimum 48-72 hours beyond symptom resolution 3
- For Streptococcus pyogenes infections, treat for at least 10 days 3
- Shake suspension well before each use 3
- Refrigeration is preferable but not required; discard unused portion after 14 days 3
Common Pitfalls to Avoid
- Do not use age-based dosing instead of weight-based dosing - this leads to underdosing in many children 8
- Do not round down significantly - maintaining the full 90 mg/kg/day dose is critical for resistant organisms 1, 2
- Do not switch to lower doses prematurely - if treatment failure occurs within 48-72 hours, reassess diagnosis rather than assuming the high dose is ineffective 1
The 250mg/5ml concentration is entirely appropriate for this dosing regimen and avoids the need for excessively large volumes that would be required with lower concentration suspensions (such as 125mg/5ml, which would require 25.2 ml per dose).