Injectable Augmentin Dosing
For adults with normal renal function, administer 1.2 g (1000 mg amoxicillin + 200 mg clavulanate) intravenously every 8 hours; for children aged 3 months to 12 years, administer 30 mg/kg every 8 hours based on the amoxicillin component, with mandatory dose reduction in renal impairment to prevent drug accumulation and toxicity.
Adult Dosing
The standard intravenous dose is 1.2 g (1000 mg amoxicillin/200 mg clavulanate) every 8 hours 1, 2. This dosing was validated in clinical studies showing 88.4% clinical cure rates with excellent local tolerance 2.
For severe infections or those requiring broader coverage, this regimen provides adequate serum concentrations while maintaining the critical amoxicillin-to-clavulanate ratio needed for β-lactamase inhibition.
Pediatric Dosing
Children 3 months to 12 years: Administer 30 mg/kg every 8 hours (based on amoxicillin component) via short IV infusion in 3-4 divided doses 3. Clinical studies using 100-200 mg/kg/day achieved complete cure or distinct improvement in all assessable pediatric cases with 92% bacteriological success 3.
Critical consideration: Critically ill children may require 25-35 mg/kg every 4-6 hours rather than every 8 hours due to augmented renal clearance, which can result in subtherapeutic concentrations and clinical failure 4. Monte Carlo simulations demonstrate that four-hourly dosing of 25 mg/kg is necessary to achieve therapeutic targets in 32% of critically ill children who otherwise experience treatment failure 4.
Renal Dose Adjustment - Critical
This is where most errors occur. Amoxicillin and clavulanate have differential renal clearance, creating a dosing challenge 5, 6.
Key Pharmacokinetic Principle
- Amoxicillin clearance decreases more dramatically than clavulanate clearance as GFR declines
- The amoxicillin:clavulanate AUC ratio increases from 4.9 at normal GFR to 14.7 in hemodialysis patients 5
- This differential clearance means standard dose reductions risk inadequate clavulanate levels while amoxicillin accumulates
Specific Adjustments by Creatinine Clearance
CrCl 10-30 mL/min:
- Reduce frequency to every 12 hours at standard dose
- Monitor for amoxicillin accumulation (CNS toxicity, seizures)
- Clavulanate levels remain more stable due to hepatic metabolism 5
CrCl <10 mL/min or Hemodialysis:
- Administer after dialysis to prevent premature drug removal
- Reduce to every 24 hours or consider alternative antibiotics
- The amoxicillin:clavulanate ratio becomes severely imbalanced (>14:1) 5
Critical pitfall: Current guidelines lack good-quality evidence for most renally cleared antibiotics in renal impairment, with inconsistencies between dosing recommendations 6. When in doubt, err toward longer dosing intervals rather than lower doses to maintain peak concentrations while preventing accumulation.
Administration Technique
- Administer via short IV infusion over 30 minutes (not bolus)
- For augmented renal clearance states, consider 1-hour infusion to optimize time above MIC 4
- Reconstitute immediately before use; solution is alkaline (pH 11) - avoid skin contact 7
Hepatic Impairment
Dose with caution and monitor hepatic function at regular intervals, as clavulanate undergoes significant hepatic metabolism 1. No specific dose reduction guidelines exist, but increased monitoring is essential.
Monitoring Requirements
- Renal function: Baseline and during therapy, especially in elderly or those with baseline impairment
- Hepatic function: If pre-existing liver disease or prolonged therapy
- Clinical response: Assess at 48-72 hours; if no improvement, consider resistance or alternative diagnosis
Common Errors to Avoid
- Substituting oral formulations: Injectable and oral Augmentin formulations are not interchangeable due to different clavulanate content 1
- Inadequate dosing in critical illness: Standard dosing fails in 32% of critically ill children due to augmented clearance 4
- Ignoring differential renal clearance: Using standard renal dosing charts without recognizing the amoxicillin-clavulanate imbalance 5
- Bolus administration: Always use infusion to prevent local reactions and optimize pharmacodynamics