Augmentin Dosing in Hemodialysis
For adults on chronic intermittent hemodialysis, administer Augmentin 500 mg/125 mg or 250 mg/125 mg every 24 hours depending on infection severity, with an additional dose both during and at the end of each dialysis session. 1
FDA-Approved Dosing Regimen
The FDA drug label provides explicit guidance for hemodialysis patients:
- Hemodialysis patients should receive 500 mg/125 mg or 250 mg/125 mg every 24 hours 1
- An additional dose must be given both during and at the end of dialysis 1
- The 875 mg/125 mg formulation should not be used in patients with GFR <30 mL/min 1
Pharmacokinetic Rationale
Both amoxicillin and clavulanic acid are significantly removed by hemodialysis, necessitating supplemental dosing:
- Hemodialysis removes approximately 64% of amoxicillin and 65% of clavulanic acid during a 4-hour session 2
- Clavulanic acid has a higher extraction ratio (0.74) compared to amoxicillin (0.44), meaning it is cleared more efficiently by dialysis 3
- The dialysis clearance for amoxicillin is 77.1 mL/min and for clavulanic acid is 92.8 mL/min 2
Critical Timing Considerations
Administer the supplemental dose at the end of dialysis rather than before to prevent premature drug removal and maintain therapeutic levels between sessions 1, 2. This approach:
- Prevents underdosing by avoiding drug removal during the dialysis session 3
- Maintains adequate serum concentrations throughout the interdialytic period 2
- Aligns with general principles for dialyzable antibiotics 4
Dosage Selection Based on Severity
Choose between the two dosing options based on infection severity:
- 500 mg/125 mg every 24 hours for more severe infections (pneumonia, complicated skin infections, pyelonephritis) 1
- 250 mg/125 mg every 24 hours for less severe infections (uncomplicated UTI, mild skin infections) 1
Important Caveats
The ratio of amoxicillin to clavulanic acid changes dramatically in renal failure, increasing from approximately 5:1 in normal renal function to 14.7:1 in hemodialysis patients 5. This occurs because:
- Amoxicillin accumulates more than clavulanic acid due to greater dependence on renal clearance 5
- Clavulanic acid maintains relatively better nonrenal clearance even in ESRD 2
- This differential accumulation is accounted for in the FDA dosing recommendations 1
Do not substitute tablet formulations interchangeably, as the 250 mg/125 mg and 500 mg/125 mg tablets contain different ratios of clavulanic acid 1.