Amiclav (Amoxicillin-Clavulanic Acid) Dosing for Pediatric Lymphadenitis
For pediatric bacterial lymphadenitis, use high-dose amoxicillin-clavulanate at 80-90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate divided into 2 doses (maximum 2g per dose) for 10-14 days. 1, 2, 3
Age-Based Dosing Algorithm
For Children Under 40 kg (Most Pediatric Patients)
High-dose regimen is the standard of care for lymphadenitis:
- 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day of clavulanate in 2 divided doses 1, 2, 3
- This provides a 14:1 ratio of amoxicillin to clavulanate, which causes less diarrhea than other formulations while maintaining efficacy 2
- Maximum single dose: 2000 mg amoxicillin per dose 2
Practical Suspension Dosing by Age
For standard infections (if high-dose not indicated):
- Ages 1-12 months: 2.5 mL of 125/31 suspension three times daily 2
- Ages 1-6 years: 5 mL of 125/31 suspension three times daily 2
- Ages 7-12 years: 5 mL of 250/62 suspension three times daily 2
- Ages 12-18 years: 1 tablet (250/125) three times daily 2
However, for lymphadenitis specifically, the high-dose twice-daily regimen is preferred over standard three-times-daily dosing. 1, 3
Why High-Dose for Lymphadenitis
Lymphadenitis requires high-dose therapy because:
- It provides adequate coverage against beta-lactamase producing organisms including Staphylococcus aureus (MSSA) and Moraxella catarrhalis 1, 3
- Standard-dose amoxicillin alone fails to provide adequate coverage for the polymicrobial nature of lymphadenitis 3
- High-dose formulation achieves tissue concentrations adequate to overcome intermediately resistant Streptococcus pneumoniae 2, 4
Treatment Duration and Monitoring
Duration:
- Continue treatment for 10-14 days total 3
- Some experts recommend continuing until the patient has been symptom-free for 7 days 3
Expected Response:
- Clinical improvement should occur within 48-72 hours of starting therapy 1, 3
- Mean defervescence time is approximately 5-6 days 5
If no improvement after 72 hours:
- Consider imaging (CT scan) to rule out complications or abscess formation 1, 3
- Reevaluate diagnosis and consider switching antibiotics 1
- Obtain cultures if not already done 1
Alternative Therapy for Penicillin Allergy
For true penicillin allergy:
- Clindamycin 30-40 mg/kg/day in 3-4 divided doses 3
- Consider linezolid or infectious disease consultation for severe infections with MRSA concerns 3
Note: Recent evidence shows oral cloxacillin is non-inferior to amoxicillin-clavulanate for uncomplicated bacterial lymphadenitis, but this is a narrower-spectrum option 5
Critical Dosing Pitfalls to Avoid
Common mistakes that lead to treatment failure:
Underdosing the amoxicillin component - Using standard 45 mg/kg/day instead of high-dose 80-90 mg/kg/day results in inadequate tissue concentrations and promotes resistance 1, 2, 3
Using amoxicillin alone - Lymphadenitis requires coverage for beta-lactamase producing organisms, which amoxicillin alone cannot provide 3
Incorrect suspension concentration - Always verify whether you're using 125/31 or 250/62 suspension before calculating volume to avoid dosing errors 2
Substituting two 250/125 tablets for one 500/125 tablet - These are NOT equivalent due to identical clavulanate content 6
Premature discontinuation - Stopping antibiotics when fever resolves rather than completing the full 10-14 day course 3
Renal Dosing Adjustments
For patients with renal impairment:
- GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours 7, 6
- GFR <10 mL/min: 500 mg or 250 mg every 24 hours 7, 6
- Hemodialysis: Give additional dose during and at end of dialysis 7, 6
Administration Tips
- Give at the start of meals to minimize gastrointestinal intolerance 7, 6
- Shake oral suspension well before each use 7
- Refrigeration is preferable but not required 7
- Discard unused suspension after 14 days 7
- Can mix suspension with formula, milk, fruit juice, or water if needed, but administer immediately 7