From the Guidelines
Zosyn (piperacillin-tazobactam) is not recommended as first-line therapy for enterococcal urinary tract infections (UTIs) due to its limited activity against these organisms. The most recent and highest quality study, 1, recommends linezolid 600 mg IV or PO every 12 hours for enterococcal infections, with the treatment duration dependent on the site of infection and clinical response. For uncomplicated urinary tract infections due to vancomycin-resistant enterococci (VRE), options such as a single dose of fosfomycin 3g PO, nitrofurantoin 100 mg PO every 6 hours, or high-dose ampicillin (18-30 g IV daily in divided doses) or amoxicillin 500 mg PO/IV every 8 hours daily are recommended, as stated in 1.
Key Considerations
- Enterococci have intrinsic resistance mechanisms that make many antibiotics less effective, including relative resistance to cephalosporins and aminoglycosides when used alone.
- The choice of antibiotic should be guided by susceptibility testing whenever possible, as enterococci can have variable resistance patterns.
- For complicated enterococcal UTIs, combination therapy may sometimes be necessary, particularly for systemic infections.
Treatment Options
- Linezolid 600 mg IV or PO every 12 hours for enterococcal infections.
- Fosfomycin 3g PO as a single dose for uncomplicated urinary tract infections due to VRE.
- Nitrofurantoin 100 mg PO every 6 hours for uncomplicated urinary tract infections due to VRE.
- High-dose ampicillin (18-30 g IV daily in divided doses) or amoxicillin 500 mg PO/IV every 8 hours daily for uncomplicated urinary tract infections due to VRE, as recommended in 1 and 1.
From the FDA Drug Label
Urinary Tract Infections caused by E. coli, Klebsiella spp., P. aeruginosa, Proteus spp., including P. mirabilis, or enterococci.
Zosyn (piperacillin) is effective for the treatment of Urinary Tract Infections (UTIs) caused by enterococci 2.
From the Research
Effectiveness of Zosyn for Enterococcus UTI
- Zosyn, also known as piperacillin/tazobactam, is a broad-spectrum antibiotic used to treat various bacterial infections, including urinary tract infections (UTIs) 3.
- However, there is limited information available on the effectiveness of Zosyn specifically for Enterococcus UTIs.
- A study published in 2022 investigated the real-world effectiveness of piperacillin/tazobactam with and without linezolid for spontaneous bacterial peritonitis, but it did not focus on Enterococcus UTIs 4.
- Another study from 2020 compared piperacillin-tazobactam with carbapenems for the treatment of nonbacteremic UTIs due to extended-spectrum beta-lactamase-producing Enterobacteriaceae, but it did not include Enterococcus species 3.
- A 2010 study discussed the treatment of resistant enterococcal UTIs, but it did not mention Zosyn as a potential treatment option 5.
- Overall, there is a lack of direct evidence on the effectiveness of Zosyn for Enterococcus UTIs, and more research is needed to determine its efficacy in this context.
Alternative Treatment Options
- According to a 2010 study, potential oral agents active against multidrug-resistant Enterococcus that may be considered for acute uncomplicated UTI include nitrofurantoin, fosfomycin, and fluoroquinolones 5.
- Parenteral agents for the treatment of pyelonephritis and complicated UTIs caused by multidrug-resistant Enterococcus include daptomycin, linezolid, and quinupristin-dalfopristin 5.
- Aminoglycosides or rifampin may be considered as adjunctive therapy in serious infections 5.
Enterococcus UTIs
- Enterococci are Gram-positive, facultative anaerobic commensal organisms of the gastrointestinal tract that are known uropathogens 6.
- Enterococcus spp. has become a leading cause of healthcare-associated infections, ranging from endocarditis to UTIs 6.
- In recent years, there has been an increase in multidrug resistance due to antibiotic misuse, especially in enterococci 6.