What is the recommended treatment for Enterococcus infections?

Treatment of Enterococcus Infections

For Enterococcus infections, ampicillin plus gentamicin is the recommended first-line treatment, with ampicillin 2g IV every 4 hours plus gentamicin 15 mg/kg/day IV/IM in 2-3 divided doses. 1

First-Line Treatment Options

Penicillin-Susceptible Enterococci

• First choice: Ampicillin + gentamicin
  • Ampicillin 2g IV every 4 hours
  • Gentamicin 15 mg/kg/day IV/IM in 2-3 divided doses
  • Target gentamicin levels: 1-hour concentration ~3 μg/mL and trough <1 μg/mL 1

Alternative Regimens

• For aminoglycoside-resistant strains: Ampicillin + ceftriaxone

  • Ampicillin 2g IV every 4 hours
  • Ceftriaxone 2g IV every 12 hours 1

• For penicillin-allergic patients: Vancomycin + gentamicin

  • Vancomycin 30 mg/kg/day IV in 2 divided doses
  • Gentamicin 15 mg/kg/day IV/IM in 2-3 divided doses 1

Treatment for Vancomycin-Resistant Enterococci (VRE)

• Linezolid: 600 mg IV/PO every 12 hours 1, 2

  • FDA-approved for VRE infections, including cases with concurrent bacteremia 2
  • Bacteriostatic agent with good tissue penetration 3

• Daptomycin: 8-12 mg/kg IV daily 1

  • Particularly effective for bloodstream infections
  • Monitor creatine kinase (CK) levels regularly 1

Treatment Duration

• Uncomplicated bacteremia: 7-14 days 1
• Endocarditis:
  • Native valve: 4-6 weeks
  • Prosthetic valve: Minimum 6 weeks 1
• Catheter-related infections: 10-14 days (with catheter removal) 1

Special Considerations

Catheter Management

• Remove any central venous catheters if present, as they may be the source of infection and lead to persistent bacteremia 1
• If catheter must be retained, use antibiotic lock therapy in addition to systemic antibiotics 1

Monitoring

• Weekly monitoring of renal function when using aminoglycosides 1
• For daptomycin therapy, regularly monitor creatine kinase levels 1
• Obtain serial blood cultures to document clearance of bacteremia 1

Diagnosis Considerations

• Differentiate between colonization and true infection before initiating therapy 1
• Consider transesophageal echocardiogram (TEE) to rule out endocarditis in patients with rising CRP despite appropriate antibiotics 1

Common Pitfalls and Caveats

• Intrinsic resistance: Enterococci have intrinsic resistance to several antibiotics, including cephalosporins when used as monotherapy 1
• Catheter removal: Failure to remove infected catheters is associated with persistent bacteremia and treatment failure 1
• Endocarditis risk: Missing endocarditis can result in treatment failure; consider infectious disease consultation for enterococcal endocarditis management 1
• Empiric treatment: Vancomycin-resistant E. faecium should only be treated empirically in high-risk patients, such as liver transplant recipients with hepatobiliary infections 1
• Linezolid considerations: Not indicated for Gram-negative infections; specific Gram-negative therapy must be initiated immediately if a concomitant Gram-negative pathogen is documented or suspected 2

Pediatric Considerations

• For pediatric patients up to 11 years: Linezolid 10 mg/kg q8h
• For pediatric patients 12 years and older: Linezolid 600 mg q12h
• Pre-term neonates less than 7 days: Linezolid 10 mg/kg q12h initially, then consider 10 mg/kg q8h if suboptimal response 2

Remember that infectious disease consultation is strongly recommended for management of enterococcal endocarditis, as this is considered standard of care 1.