Renal Dosing for Augmentin (Amoxicillin-Clavulanate)
For patients with GFR <30 mL/min, avoid the 875/125 mg formulation entirely and use 500/125 mg or 250/125 mg every 12 hours for moderate infections (GFR 10-30 mL/min) or every 24 hours for severe renal impairment (GFR <10 mL/min), with hemodialysis patients receiving an additional dose during and after dialysis. 1
Dosing Algorithm by Renal Function
Normal to Mild Renal Impairment (GFR >30 mL/min)
- Use standard dosing regimens without adjustment 2
- All formulations including 875/125 mg tablets are appropriate 1
Moderate Renal Impairment (GFR 10-30 mL/min)
- Reduce dose by approximately 50% OR double the dosing interval 2
- Specific FDA-approved regimen: 500/125 mg or 250/125 mg every 12 hours (based on infection severity) 1
- The 875/125 mg formulation is contraindicated in this population 1
Severe Renal Impairment (GFR <10 mL/min)
- Further reduction to 25-50% of normal dose is required 2
- Specific FDA-approved regimen: 500/125 mg or 250/125 mg every 24 hours (based on infection severity) 1
- The 875/125 mg formulation is contraindicated 1
Hemodialysis Patients
- Administer 500/125 mg or 250/125 mg every 24 hours (depending on severity) 1
- Give an additional dose both during and at the end of dialysis 1
- Post-dialysis dosing is crucial to avoid premature drug removal and ensure adequate exposure 2, 3
- Administering before dialysis wastes medication and leaves patients undertreated 2
Critical Considerations and Pitfalls
Formulation Selection Matters
- Do NOT substitute two 250/125 mg tablets for one 500/125 mg tablet - they contain different amounts of clavulanic acid (250 mg total vs. 125 mg) 1
- The 250/125 mg tablet and 250/62.5 mg chewable tablet are not interchangeable 1
Monitoring Requirements
- Patients with borderline renal function may require 24-hour urine collection to accurately define the degree of impairment before making regimen changes 2
- Close monitoring for adverse effects is warranted, as drug accumulation can occur with any degree of renal insufficiency 2
- Renal function should be reassessed when clinically indicated throughout treatment 4, 5
Common Dosing Errors to Avoid
- Assuming all antibiotics require the same degree of dosage adjustment is incorrect - individualized adjustments based on specific drug properties are necessary 2
- Drug dosing errors are common in patients with renal impairment and can cause adverse effects and poor outcomes 5
- Non-adherence to dosing guidelines has the potential to cause moderate to severe harm in 71.4% of cases 6
Pharmacokinetic Rationale
- Renal impairment affects more than just renal drug elimination - it also impacts plasma protein binding, distribution, and metabolism 4
- Amoxicillin-clavulanate is primarily renally cleared, making dose adjustment essential to prevent drug accumulation 7, 8
- The dosing interval extension (from every 12 hours to every 24 hours) accounts for the prolonged elimination half-life in severe renal dysfunction 7