Amoxicillin-Clavulanate Dosing for Dialysis Exit Site Infection
For a hemodialysis patient with an exit site infection, administer amoxicillin-clavulanate 500 mg/125 mg every 24 hours, with an additional dose both during and at the end of each dialysis session. 1
Primary Dosing Recommendation
The FDA-approved dosing for hemodialysis patients is 500 mg/125 mg or 250 mg/125 mg every 24 hours depending on infection severity, with supplemental dosing during and at the end of dialysis. 1
For exit site infections in dialysis patients, which are typically moderate severity, the 500 mg/125 mg dose every 24 hours is most appropriate. 1
The timing is critical: administer the dose after hemodialysis sessions to prevent premature drug removal and maintain therapeutic levels. 2, 1
Rationale for Dosing Adjustment
Both amoxicillin and clavulanic acid are cleared by hemodialysis, but clavulanic acid has a higher extraction ratio (0.74) compared to amoxicillin (0.44), meaning it is removed more efficiently during dialysis. 3
The differential clearance results in an altered ratio of amoxicillin to clavulanic acid during dialysis days, which necessitates supplemental dosing to maintain adequate clavulanic acid concentrations. 4, 3
Patients with glomerular filtration rate <10 mL/min (which includes hemodialysis patients) require the 24-hour dosing interval rather than the standard 12-hour interval to prevent drug accumulation. 1
Critical Timing Considerations
Never administer amoxicillin-clavulanate before dialysis, as this will result in subtherapeutic levels due to drug removal during the session. 2
The supplemental dose during and at the end of dialysis compensates for the significant drug removal, particularly of clavulanic acid. 1
High-flux hemodialysis increases clearance of both compounds even more than traditional dialysis, making the supplemental dosing even more critical. 5
Monitoring Requirements
The American College of Physicians recommends monitoring renal function during treatment in patients with severely impaired renal function, though this is less relevant for established hemodialysis patients. 6
Watch for drug accumulation signs, as even with dose adjustments, some accumulation can occur in patients with end-stage renal disease. 2
Common Pitfalls to Avoid
Do not use the 875 mg/125 mg formulation in dialysis patients—this dose is contraindicated when GFR is <30 mL/min. 1
Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet, as they contain different amounts of clavulanic acid and are not equivalent. 1
Avoid once-daily dosing without supplemental doses, as simulations show this results in only 20-30% probability of achieving adequate clavulanic acid concentrations. 5
Do not assume standard dosing intervals apply—the 12-hour interval used in patients with normal renal function will cause excessive accumulation in dialysis patients. 1, 4