Can Zosyn (piperacillin-tazobactam) be used to treat Pseudomonas aeruginosa bacteremia?

From the Guidelines

Yes, Zosyn (piperacillin-tazobactam) can be used to treat pseudomonal bacteremia, as recommended by the most recent guidelines. According to the study published in the Journal of Microbiology, Immunology and Infection in 2022 1, piperacillin-tazobactam is listed as a recommended treatment option for infections due to carbapenem-resistant Pseudomonas aeruginosa (CRPA) and difficult-to-treat P. aeruginosa (DTR-PA). The typical adult dosage is 3.375-4.5 g IV q6h, with adjustments needed for patients with renal impairment.

Key Considerations

• Treatment duration typically ranges from 5-14 days depending on the source of infection, clinical response, and patient factors.
• Zosyn works by inhibiting bacterial cell wall synthesis and provides coverage against many Pseudomonas aeruginosa strains, though local resistance patterns should be considered.
• In critically ill patients or those with risk factors for resistant organisms, combination therapy with an aminoglycoside or fluoroquinolone might be initially warranted until susceptibility results are available.
• Regular monitoring of renal function, clinical response, and potential adverse effects such as diarrhea or allergic reactions is important during treatment.

Additional Recommendations

• The study also recommends considering anti-pseudomonal penicillins or cephalosporins combined with aminoglycosides when the antimicrobial susceptibility testing results are interpreted as susceptible 1.
• For patients with pseudomonal bacteremia, combination therapy with an extended-spectrum beta-lactam and either an aminoglycoside or a fluoroquinolone is suggested, as recommended by the Surviving Sepsis Campaign in 2012 1.

Important Notes

• The choice of antibiotic therapy should be guided by local antimicrobial resistance patterns and susceptibility testing results.
• The treatment regimen may need to be adjusted based on the patient's clinical response and the results of antimicrobial susceptibility testing.

From the FDA Drug Label

1. 2 Nosocomial Pneumonia Piperacillin and tazobactam for injection, USP is indicated in adults and pediatric patients (2 months of age and older) for the treatment of nosocomial pneumonia (moderate to severe) caused by beta-lactamase producing isolates of Staphylococcus aureus and by piperacillin and tazobactam-susceptible Acinetobacter baumannii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa (Nosocomial pneumonia caused by P. aeruginosa should be treated in combination with an aminoglycoside) [see Dosage and Administration (2)].

Zosyn (piperacillin/tazobactam) can be used to cover for Pseudomonal bacteremia, but it should be used in combination with an aminoglycoside for nosocomial pneumonia caused by P. aeruginosa 2.

• The recommended dosage for nosocomial pneumonia is 4.5 g every six hours plus an aminoglycoside, administered by intravenous infusion over 30 minutes.
• The recommended duration of piperacillin and tazobactam for injection treatment for nosocomial pneumonia is 7 to 14 days.
• Treatment with the aminoglycoside should be continued in patients from whom P. aeruginosa is isolated 2.

From the Research

Zosyn (Piperacillin-Tazobactam) for Pseudomonal Bacteremia

• Zosyn, also known as piperacillin-tazobactam, is a broad-spectrum antibiotic used to treat various bacterial infections, including those caused by Pseudomonas aeruginosa.
• According to a study published in 2020 3, piperacillin-tazobactam was found to be effective as a definitive monotherapy for P. aeruginosa bacteremia, with no significant difference in mortality, clinical, and microbiological outcomes compared to ceftazidime and carbapenems.
• Another study published in 2024 4 found no evidence of clinical benefit differences among direct antibiotic comparisons, including piperacillin-tazobactam, for the treatment of P. aeruginosa infection.
• A study from 2002 5 compared the synergistic activities of piperacillin-tazobactam and cefepime when combined with gentamicin, ciprofloxacin, or levofloxacin against P. aeruginosa, and found that all combinations were bactericidal, with no statistical difference in the frequency of synergy between the beta-lactam plus gentamicin and the beta-lactams plus fluoroquinolone combinations.
• A retrospective study published in 2015 6 found that piperacillin-tazobactam was effective in treating P. aeruginosa bacteremia, with a clinical cure rate of 77% and bacterial eradication rate of 87%.
• An updated review of piperacillin-tazobactam published in 1999 7 highlighted its effectiveness in treating various bacterial infections, including those caused by P. aeruginosa, and its potential use in combination with an aminoglycoside for severe nosocomial infections.

Efficacy of Zosyn for Pseudomonal Bacteremia

• The studies suggest that Zosyn (piperacillin-tazobactam) can be used to cover for pseudomonal bacteremia, with effective clinical and microbiological outcomes.
• However, the choice of antibiotic should be based on the specific circumstances of each patient, including the severity of the infection, the susceptibility of the organism, and the potential for resistance.
• It is essential to note that the use of Zosyn should be guided by local antimicrobial stewardship policies and susceptibility patterns.