What is the appropriate intravenous co‑amoxiclav (amoxicillin‑clavulanate) dosing regimen for an adult on intermittent hemodialysis with a central‑line associated bloodstream infection due to Enterococcus faecalis?

Co-Amoxiclav Dosing for Enterococcus faecalis CLABSI in Hemodialysis Patients

For an adult hemodialysis patient with E. faecalis CLABSI, administer amoxicillin-clavulanate 500 mg/125 mg IV every 24 hours (after each dialysis session), with an additional dose both during and at the end of dialysis. 1

Dosing Rationale and Adjustments

Standard Hemodialysis Dosing

• Amoxicillin-clavulanate 500 mg/125 mg IV every 24 hours is the FDA-approved regimen for hemodialysis patients, with supplemental dosing during and after dialysis sessions 1
• The 875 mg/125 mg dose should not be used in patients with GFR <30 mL/min 1
• An additional dose must be administered both during and at the end of each dialysis session to compensate for drug removal 1

Alternative if Beta-Lactamase Production Suspected

• If beta-lactamase production is suspected (though unlikely with susceptible E. faecalis), amoxicillin-clavulanate remains appropriate as the clavulanate component inhibits beta-lactamase 2
• The ESC guidelines specifically recommend replacing ampicillin with ampicillin-sulbactam or amoxicillin with amoxicillin-clavulanate when beta-lactamase production is documented 2

Treatment Duration

A 7-day treatment course is appropriate for uncomplicated enterococcal CLABSI after catheter removal. 3

• Recent multicenter data demonstrates that ≤7 days of treatment for enterococcal CLABSI shows no difference in 30-day mortality compared to longer courses (HR 0.41,95% CI 0.13-1.24, p=0.12) 3
• This shorter duration applies specifically to non-complicated cases without endocarditis or metastatic infection 3
• Catheter removal should occur within a median of 3 days (ideally within 1-8 days) 3

Critical Management Steps

Catheter Management

• Remove the central line within 3 days of initiating antibiotic therapy 3
• Catheter removal is essential for treatment success; failure to remove infected catheters results in 39% treatment failure rates 4
• Persistent fever beyond 48 hours after antibiotic initiation suggests treatment failure and warrants further investigation 4

Monitoring Requirements

• Monitor for persistent fever beyond 48 hours, which indicates treatment failure 4
• Watch for serious complications including endocarditis (1.6% incidence) and osteomyelitis (4.7% incidence), which occur more frequently with treatment failure (16% vs 0%, p=0.01) 4
• Renal function monitoring is less critical with beta-lactams compared to aminoglycoside-containing regimens, but still recommended 2

When to Consider Alternative Regimens

For Penicillin Allergy

• Vancomycin 20 mg/kg loading dose IV during the last hour of dialysis, then 500 mg IV during the last 30 minutes of each subsequent dialysis session 2
• Target vancomycin trough concentrations of 10-20 μg/mL 2

For Complicated Infections (Endocarditis Suspected)

• If endocarditis cannot be excluded, use ampicillin 2 g IV every 4 hours (200 mg/kg/day in 4-6 divided doses) for 4-6 weeks 2
• Consider adding gentamicin 3 mg/kg/day IV in 1 dose for the first 2 weeks if aminoglycoside-susceptible, though this adds nephrotoxicity risk in dialysis patients 2
• The ampicillin-ceftriaxone combination (ampicillin 2 g IV every 4 hours + ceftriaxone 2 g IV every 12 hours) is effective for E. faecalis with high-level aminoglycoside resistance 2

Common Pitfalls to Avoid

• Do not use the 875 mg/125 mg formulation in dialysis patients (GFR <30 mL/min) 1
• Do not forget supplemental dosing during and after dialysis sessions, as amoxicillin is dialyzable 1
• Do not delay catheter removal beyond 3 days, as this significantly increases treatment failure risk 3, 4
• Do not extend treatment beyond 7 days for uncomplicated CLABSI after catheter removal, as longer courses provide no additional benefit 3
• Do not assume endocarditis is absent without proper evaluation; dialysis patients with persistent bacteremia despite catheter removal and antibiotics require echocardiography 5