From the Guidelines
For enterococcus bacteremia and UTI, linezolid 600 mg IV or PO every 12 hours is recommended as the first-line treatment, with the treatment duration dependent on the site of infection and clinical response. This recommendation is based on the strongest and most recent evidence available, as outlined in the guidelines for the treatment of infections due to multidrug-resistant organisms 1.
Key Considerations
- The choice of antibiotic should be guided by susceptibility testing, as enterococci can have variable resistance patterns, including vancomycin-resistant enterococci (VRE) which may require alternative treatments such as linezolid or daptomycin 1.
- For VRE bacteremia, high-dose daptomycin (8-12 mg/kg/day) or in combination with beta-lactams (including penicillins, carbapenems, and cephalosporins) is recommended, with the duration of treatment typically ranging from 10 to 14 days 1.
- For uncomplicated urinary tract infections due to VRE, options include a single dose of fosfomycin 3g PO, nitrofurantoin 100mg PO every 6 hours, or high-dose ampicillin (18-30g IV daily in divided doses) or amoxicillin 500mg PO/IV every 8 hours, with treatment duration usually between 3 to 7 days 1.
- Source control, such as removing infected catheters or draining abscesses, is crucial for successful treatment, and monitoring renal function is important when using certain antibiotics due to their potential nephrotoxicity 1.
Treatment Options
- Linezolid 600 mg IV or PO every 12 hours for enterococcal infections, including bacteremia and UTI, with treatment duration based on the site of infection and clinical response 1.
- Daptomycin 8-12 mg/kg IV daily for VRE bacteremia, potentially in combination with beta-lactams, with a treatment duration of at least 10 to 14 days 1.
- Fosfomycin 3g PO single dose, nitrofurantoin 100mg PO every 6 hours, or high-dose ampicillin (18-30g IV daily in divided doses) or amoxicillin 500mg PO/IV every 8 hours for uncomplicated urinary tract infections due to VRE, with treatment duration typically between 3 to 7 days 1.
From the FDA Drug Label
Daptomycin has been shown to be active against most isolates of the following microorganisms both in vitro and in clinical infections [see Indications and Usage (1)] Gram-Positive Bacteria Enterococcus faecalis (vancomycin-susceptible isolates only) Staphylococcus aureus (including methicillin-resistant isolates) Streptococcus agalactiae Streptococcus dysgalactiae subsp. equisimilis Streptococcus pyogenes
Daptomycin may be effective against Enterococcus faecalis (vancomycin-susceptible isolates only) and is used to treat complicated skin and skin structure infections. However, there is limited information on its effectiveness for enterococcus bacteremia and UTI.
- Key points:
- Daptomycin is effective against vancomycin-susceptible Enterococcus faecalis.
- Limited information is available on its effectiveness for enterococcus bacteremia and UTI.
- Daptomycin is used to treat complicated skin and skin structure infections. 2
From the Research
Antibiotic Options for Enterococcus Bacteremia and UTI
- For the treatment of enterococcus bacteremia, studies suggest that daptomycin and linezolid are potential options 3, 4, 5, 6, 7.
- However, the comparison of linezolid and daptomycin for vancomycin-resistant enterococcal bacteremia shows mixed results, with some studies indicating higher mortality rates with daptomycin 6 and others suggesting higher treatment failure rates with linezolid 7.
- For urinary tract infections (UTIs) caused by enterococci, potential oral agents include nitrofurantoin, fosfomycin, and fluoroquinolones, while parenteral agents such as daptomycin, linezolid, and quinupristin-dalfopristin may be considered for complicated UTIs 3, 4.
- Aminoglycosides or rifampin may be used as adjunctive therapy in serious infections 3.
- Newer agents such as tedizolid and oritavancin have shown good in vitro activity against vancomycin-resistant enterococci, but clinical studies are limited 4, 5.
Considerations for Treatment
- The choice of antibiotic should be guided by urine culture and susceptibility results 3.
- Removal of indwelling urinary catheters should be considered in patients with UTIs caused by enterococci 3.
- Combination therapy may be warranted in complex infections, while monotherapy may be sufficient for uncomplicated infections 4, 5.
- The pharmacokinetics, efficacy, and safety of certain antibiotics, such as tigecycline and quinupristin/dalfopristin, can be problematic for severe infections 4.