Augmentin Dosing for eGFR 49.5 mL/min/1.73 m²
For a patient with eGFR 49.5 mL/min/1.73 m² (CKD Stage 3a), standard Augmentin dosing can be used without dose adjustment, as renal dose modifications are only required when eGFR falls below 30 mL/min/1.73 m². 1
Rationale for Standard Dosing
No dose adjustment is necessary for eGFR >30 mL/min/1.73 m² because both amoxicillin and clavulanic acid maintain adequate clearance at this level of renal function 1
The pharmacokinetic study in patients with varying degrees of renal impairment demonstrated that total body clearance of both amoxicillin and clavulanic acid remains sufficient until GFR drops below 35 mL/min/1.73 m² 1
At eGFR 49.5 mL/min/1.73 m², the patient falls into the GFR range of 35-75 mL/min, where the ratio of amoxicillin to clavulanic acid exposure (5.3 ± 2.4) remains close to normal (4.9 ± 1.2 at GFR 75 mL/min), indicating balanced drug disposition 1
Recommended Dosing Regimens
Standard adult dosing options include:
- 875 mg/125 mg orally twice daily for most infections 2
- 500 mg/125 mg orally three times daily as an alternative for less severe infections 2
- 1000 mg/200 mg intravenously every 8 hours for severe infections requiring parenteral therapy 3, 4
Important Clinical Considerations
Monitor renal function periodically during treatment, as acute changes in kidney function could necessitate dose adjustment if eGFR drops below 30 mL/min/1.73 m² 5
Dose reduction becomes necessary only when eGFR <30 mL/min/1.73 m², at which point the dosing interval should be extended or the dose reduced to prevent amoxicillin accumulation while maintaining adequate clavulanic acid levels 1
The most pronounced accumulation occurs with amoxicillin rather than clavulanic acid in renal impairment, as clavulanic acid maintains relatively preserved non-renal clearance 1, 3
Common Pitfalls to Avoid
Do not unnecessarily reduce the dose in patients with eGFR >30 mL/min/1.73 m², as this may lead to subtherapeutic levels and treatment failure 1
Avoid confusing CKD stage with dosing requirements: CKD Stage 3a (eGFR 45-59) and 3b (eGFR 30-44) both allow standard dosing, while dose adjustment is reserved for Stage 4 and beyond (eGFR <30) 5
Be aware that gastrointestinal side effects (nausea, vomiting, diarrhea) occur with similar frequency regardless of renal function and are not an indication for dose reduction 2