From the Guidelines
Ampicillin or amoxicillin is the first-line antibiotic for treating enterococcal urinary tract infections (UTIs) in patients with uncomplicated infections and no allergies. The typical dosage for ampicillin is 500 mg orally four times daily for 7-10 days, while amoxicillin is usually prescribed as 500 mg three times daily for the same duration 1. For patients with penicillin allergies, nitrofurantoin (100 mg twice daily for 5-7 days) or fosfomycin (3 g single dose) are appropriate alternatives, as recommended by recent guidelines 1.
Key Considerations
- Treatment choice should be guided by susceptibility testing whenever possible, as enterococci have increasing resistance patterns 2, 3, 1.
- Enterococci are naturally resistant to cephalosporins and trimethoprim-sulfamethoxazole, so these should be avoided 1.
- Asymptomatic bacteriuria generally doesn't require treatment except in pregnant women or before urologic procedures.
- Enterococci are part of normal gut flora but can cause UTIs, particularly in hospitalized patients or those with structural abnormalities of the urinary tract.
Alternative Options
- For complicated infections or resistance, combination therapy with ampicillin plus gentamicin may be necessary, or vancomycin for resistant strains 2, 3.
- Linezolid 600 mg IV or PO every 12 hours is recommended for enterococcal infections, with treatment duration dependent on the site of infection and clinical response 2, 3.
- High-dose daptomycin 8-12 mg/kg/day or in combination with beta-lactams is recommended for VRE bacteremia 2, 3.
Duration of Treatment
- The duration of treatment should be individualized according to infection sites, source control, underlying comorbidities, and initial response to therapy 1.
- For uncomplicated urinary tract infections, treatment duration is typically 3-7 days 1.
From the FDA Drug Label
The cure rates for the ITT population with documented vancomycin-resistant enterococcal infection at baseline are presented in Table 15 by source of infection. Urinary tract: 12/19 (63) for ZYVOX 600 mg
The antibiotic of choice to treat enterococcus in the urine is linezolid.
- The cure rate for linezolid-treated patients with urinary tract infections was 63% 4. Note that vancomycin-resistant enterococcal infections were included in the study. Daptomycin may also be effective against enterococcal infections, but the provided data does not specifically address its use in urinary tract infections 5.
From the Research
Antibiotic Treatment for Enterococcus in Urine
- The choice of antibiotic for treating enterococcus in the urine depends on the susceptibility of the enterococcal strain and the severity of the infection 6, 7.
- For ampicillin-susceptible enterococcal UTIs, ampicillin is generally considered the drug of choice 6.
- For vancomycin-resistant enterococcal (VRE) UTIs, potential oral options include nitrofurantoin, fosfomycin, and doxycycline 6, 7.
- Linezolid and daptomycin are reserved for confirmed or suspected upper and/or bacteremic VRE UTIs among ampicillin-resistant strains 6.
- Aminopenicillins, such as ampicillin, may be effective in treating ampicillin-resistant enterococcal UTIs due to high concentrations in the urine 8.
Considerations for Treatment
- Removal of indwelling urinary catheters should be considered to prevent further infection 7.
- Antibiotic therapy selection should be guided by urine culture and susceptibility results 7.
- Routine therapy for asymptomatic bacteriuria with multidrug-resistant Enterococcus is not recommended 7.
- Treatment of enterococcal UTIs should be based on the most recent guidelines and take into account the pathogenicity, epidemiology, and treatment recommendations for enterococci 9.