What is the recommended amoxicillin‑clavulanate dosing for a pediatric patient, including dose augmentation for severe infections and adjustments for renal impairment?

Amoxicillin-Clavulanate Dosing for Pediatric Patients

For pediatric patients ≥3 months old with severe infections requiring augmented dosing, use 90 mg/kg/day of the amoxicillin component divided every 12 hours (45 mg/kg/dose), or 40 mg/kg/day divided every 8 hours for the standard formulation. 1, 2

Standard Dosing by Age and Severity

Neonates and Infants <3 months

• 30 mg/kg/day divided every 12 hours (based on amoxicillin component)
• Use the 125 mg/5 mL oral suspension formulation 3

Patients ≥3 months old

For severe infections (otitis media, sinusitis, lower respiratory tract infections):

• 45 mg/kg/day every 12 hours using 200 mg/5 mL or 400 mg/5 mL suspension
• Alternative: 40 mg/kg/day every 8 hours using 125 mg/5 mL or 250 mg/5 mL suspension 3

For less severe infections:

• 25 mg/kg/day every 12 hours, or
• 20 mg/kg/day every 8 hours 3

Patients ≥40 kg

Dose according to adult recommendations:

• Standard: 500 mg/125 mg every 12 hours or 250 mg/125 mg every 8 hours
• Severe infections/respiratory tract: 875 mg/125 mg every 12 hours or 500 mg/125 mg every 8 hours 3

Critical Considerations for Augmented Dosing

Critically Ill Children

In critically ill pediatric patients, particularly those post-cardiac surgery or in ICU settings, standard dosing is frequently inadequate due to augmented renal clearance. Recent pharmacokinetic studies demonstrate that:

• Four-hourly dosing (every 4 hours instead of every 6 hours) is required to achieve therapeutic targets in patients with augmented clearance 4, 5
• Standard 6-hourly dosing results in subtherapeutic concentrations in 32% of critically ill children, leading to clinical failure 5
• Only patients receiving vasopressors maintain adequate drug exposure with standard 6-hourly dosing, as vasopressors decrease clearance by approximately one-third 4

Practical algorithm for critically ill children:

1. If on vasopressors: Use standard 6-hourly dosing (25-35 mg/kg every 6 hours)
2. If NOT on vasopressors: Increase to 4-hourly dosing (25 mg/kg every 4 hours) 4, 5
3. Consider 1-hour infusion rather than bolus dosing in patients with augmented renal function 5

Renal Impairment Adjustments

GFR 10-30 mL/min:

• 500 mg/125 mg or 250 mg/125 mg every 12 hours (severity-dependent) 3

GFR <10 mL/min:

• 500 mg/125 mg or 250 mg/125 mg every 24 hours (severity-dependent) 3

Hemodialysis patients:

• 500 mg/125 mg or 250 mg/125 mg every 24 hours
• Additional dose during and at end of dialysis 3
• Fractional drug removal during hemodialysis is approximately 64% for amoxicillin and 65% for clavulanate 6

Important Formulation Warnings

Do NOT substitute formulations interchangeably:

• Two 250 mg/125 mg tablets ≠ one 500 mg/125 mg tablet (same clavulanate content)
• 250 mg/125 mg tablet ≠ 250 mg/62.5 mg chewable tablet (different clavulanate ratios)
• The 250 mg/125 mg tablet should not be used until child weighs ≥40 kg 3

Administration Recommendations

• Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 3
• The every 12-hour regimen is preferred over every 8-hour dosing as it significantly reduces diarrhea incidence 3

Common Pitfalls

1. Underdosing in critically ill children: Standard dosing fails in 32% of ICU patients due to augmented clearance—consider 4-hourly dosing 5
2. Forgetting dialysis supplementation: Always give additional doses during and after hemodialysis 3
3. Using adult formulations in small children: The 875 mg/125 mg dose should not be used in patients with GFR <30 mL/min 3
4. Incorrect formulation substitution: Different formulations contain different clavulanate ratios and are not interchangeable 3