From the Guidelines
Yes, Zosyn (piperacillin/tazobactam) is effective against Bacteroides species, including Bacteroides fragilis, as it combines piperacillin with tazobactam, a beta-lactamase inhibitor that enhances its activity against beta-lactamase-producing strains of Bacteroides 1.
Key Points to Consider
- Zosyn's effectiveness against Bacteroides species is due to its mechanism of action, which involves inhibiting bacterial cell wall synthesis, making it valuable for treating mixed aerobic and anaerobic infections such as intra-abdominal infections 1.
- The addition of tazobactam to piperacillin enhances its activity against beta-lactamase-producing strains of Bacteroides, which are resistant to many other beta-lactam antibiotics 1.
- While resistance rates to Zosyn among Bacteroides species remain relatively low, it is crucial to consider local resistance patterns when selecting this antibiotic for serious infections 1.
- The typical adult dosage of Zosyn is 3.375g or 4.5g administered intravenously every 6-8 hours, with adjustments needed for patients with renal impairment.
Clinical Use and Resistance
- Zosyn is particularly useful for treating infections where Bacteroides species are often involved, such as intra-abdominal infections, complicated skin infections, and aspiration pneumonia 1.
- The use of Zosyn should be guided by susceptibility testing and local epidemiology of resistance to ensure its effectiveness and to minimize the development of resistance 1.
- As with all antibiotics, the use of Zosyn should be rational and appropriate to optimize clinical care and reduce the selection pressure on resistant pathogens 1.
From the FDA Drug Label
Piperacillin and tazobactam has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections ... Anaerobic bacteria Bacteroides fragilis group (B. fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgatus)
Zosyn (piperacillin/tazobactam) is effective against Bacteroides species, including B. fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgatus 2.
From the Research
Effectiveness of Zosyn against Bacteroides
- Zosyn, also known as piperacillin/tazobactam, is a broad-spectrum antibiotic that covers a wide range of Gram-positive and Gram-negative aerobic and anaerobic bacteria, including Bacteroides species 3.
- The combination of piperacillin and tazobactam provides effective coverage against many pathogens producing beta-lactamases, which are enzymes that can inactivate certain antibiotics 4.
- Studies have shown that piperacillin/tazobactam is effective against Bacteroides species, including Bacteroides fragilis, which is a common cause of intra-abdominal infections 3, 4.
- Piperacillin/tazobactam has been compared to other antibiotics, such as imipenem and ticarcillin/clavulanate, and has been shown to be equally or more effective in treating infections caused by Bacteroides species 3, 4.
Spectrum of Activity
- The spectrum of activity of piperacillin/tazobactam includes:
- Gram-positive aerobic bacteria, such as Staphylococcus aureus and Streptococcus pneumoniae
- Gram-negative aerobic bacteria, such as Escherichia coli and Klebsiella pneumoniae
- Anaerobic bacteria, such as Bacteroides fragilis and Clostridium difficile
- Piperacillin/tazobactam is also effective against many bacteria that produce beta-lactamases, which can inactivate certain antibiotics 3, 4.
Clinical Use
- Piperacillin/tazobactam is commonly used to treat a variety of infections, including:
- Intra-abdominal infections, such as appendicitis and peritonitis
- Skin and soft tissue infections, such as cellulitis and abscesses
- Urinary tract infections, such as pyelonephritis and cystitis
- Respiratory tract infections, such as pneumonia and bronchitis
- Piperacillin/tazobactam may be used as an alternative to carbapenems in certain situations, such as in patients with ESBL-producing organisms 5.