From the Guidelines
Ampicillin or amoxicillin are the preferred empiric antibiotics for enterococcal UTIs while awaiting culture and sensitivity results. For uncomplicated infections, amoxicillin 500 mg three times daily or ampicillin 500 mg four times daily for 5-7 days is typically effective, as recommended by recent guidelines 1. In patients with penicillin allergies, nitrofurantoin 100 mg twice daily for 5-7 days is a reasonable alternative, with a weak recommendation and very low quality of evidence 1.
Key Considerations
- For more severe infections or complicated cases, ampicillin plus gentamicin may be necessary for synergistic activity.
- Vancomycin should be reserved for cases with suspected resistant strains or in critically ill patients.
- Enterococci are intrinsically resistant to cephalosporins and trimethoprim-sulfamethoxazole, so these should be avoided.
- Once susceptibility results are available, therapy should be adjusted accordingly.
Treatment Options
- Fosfomycin 3 g PO x 1 dose or 3 g PO qod is also an option for uncomplicated urinary tract infections due to VRE, with a weak recommendation and very low quality of evidence 1.
- Linezolid 600 mg IV q12 h is recommended for enterococcal infections, including complicated urinary tract infections, with a strong recommendation and low quality of evidence 1.
- Daptomycin 6e12 mg/kg IV qd is also an option for complicated urinary tract infections, with a weak recommendation and low quality of evidence 1.
Duration of Treatment
- The duration of treatment should be individualized according to infection sites, source control, the underlying comorbidities, and the initial response to therapy, as recommended by recent guidelines 1.
From the FDA Drug Label
Levofloxacin has in vitro activity against Gram-negative and Gram-positive bacteria fections as described in Indications and Usage (1): Gram-PositiveBacteria Enterococcus faecalis
The antibiotic that covers Enterococcus UTI until a biogram is out is levofloxacin 2.
- Key points:
- Levofloxacin has in vitro activity against Enterococcus faecalis.
- The drug label does not provide information on the specific coverage of Enterococcus species other than Enterococcus faecalis.
- However, based on the available information, levofloxacin can be considered as an option for treating Enterococcus UTI until a biogram is available.
From the Research
Antibiotic Options for Enterococcus UTI
- Ampicillin is generally considered the drug of choice for ampicillin-susceptible enterococcal UTIs, including VRE 3.
- Nitrofurantoin, fosfomycin, and doxycycline have intrinsic activity against enterococci, including VRE, and are possible oral options for VRE cystitis 3, 4.
- Linezolid and daptomycin should be reserved for confirmed or suspected upper and/or bacteremic VRE UTIs among ampicillin-resistant strains 3, 4.
- Quinupristin-dalfopristin and tigecycline may be considered on a case-by-case basis due to concerns of toxicity, resistance, and insufficient supportive data 3, 4.
Empiric Treatment of Enterococcus UTI
- Until the biogram is available, empiric treatment options may include ampicillin, nitrofurantoin, fosfomycin, or doxycycline, depending on the suspected susceptibility of the enterococcal isolate 3, 4.
- Linezolid may be considered for empiric treatment of VRE UTI, especially in cases where the isolate is suspected to be resistant to other antibiotics 5, 6.
Susceptibility Patterns of VRE
- Vancomycin-resistant E. faecium isolates are often susceptible to linezolid, but may be resistant to other antibiotics such as ampicillin, ciprofloxacin, nitrofurantoin, and tetracycline 7.
- Vancomycin-resistant E. faecalis isolates may be susceptible to ampicillin, linezolid, and nitrofurantoin, but resistant to ciprofloxacin and tetracycline 7.