Renal Dose Adjustment for Augmentin
For patients with renal impairment, Augmentin dosing must be adjusted based on glomerular filtration rate (GFR): use standard dosing for GFR >30 mL/min, reduce to 500/125 mg or 250/125 mg every 12 hours for GFR 10-30 mL/min, reduce to every 24 hours for GFR <10 mL/min, and administer an additional dose both during and at the end of dialysis for hemodialysis patients. 1
Standard Dosing Parameters
- Patients with mild renal impairment (GFR >30 mL/min) do not require dose reduction and can receive standard dosing regimens 2, 1
- The 875/125 mg formulation is contraindicated in patients with GFR <30 mL/min 1
Moderate Renal Impairment (GFR 10-30 mL/min)
- Reduce dose to 500/125 mg or 250/125 mg every 12 hours depending on infection severity 1
- This represents approximately a 50% dose reduction or doubling of the dosing interval compared to standard regimens 2
- Both amoxicillin and clavulanic acid are renally eliminated, requiring parallel dose adjustments 3
Severe Renal Impairment (GFR <10 mL/min)
- Reduce dose to 500/125 mg or 250/125 mg every 24 hours based on infection severity 1
- This represents a further dose reduction to 25-50% of the normal dose 2
- Clavulanic acid accumulation can occur in severe renal impairment, though it maintains a favorable safety profile 3
Hemodialysis Patients
- Administer 500/125 mg or 250/125 mg every 24 hours depending on infection severity 1
- Give an additional dose both during and at the end of dialysis to compensate for drug removal 1
- Post-dialysis administration is crucial to ensure adequate drug exposure and avoid premature clearance 2
- Administering before dialysis wastes medication and leaves patients undertreated 2
Critical Monitoring Considerations
- Patients with borderline renal function (GFR 30-50 mL/min) 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
- Avoid concomitant nephrotoxic agents such as aminoglycosides and NSAIDs in patients with baseline renal impairment 3
- Consult nephrology before prescribing in patients on dialysis or with GFR <30 mL/min to optimize dosing and minimize toxicity 3
Special Populations
- For continuous renal replacement therapy (CRRT), consider maintaining higher individual doses with extended intervals, though specific coamoxiclav data is limited 3
- Consider therapeutic drug monitoring in critically ill patients with fluctuating renal function 3
Common Pitfalls to Avoid
- Do not substitute two 250/125 mg tablets for one 500/125 mg tablet, as both contain the same amount of clavulanic acid (125 mg), making them non-equivalent 1
- Do not assume all antibiotics require the same degree of dosage adjustment in renal impairment; individualized adjustments are necessary 2
- Do not use estimated GFR formulas at extremes of body mass without adjusting for body surface area, particularly for drugs with narrow therapeutic ranges 4