From the Guidelines
Ceftazidime (Ceftaz) primarily covers gram-negative bacteria, including Pseudomonas aeruginosa, which is one of its distinguishing features among third-generation cephalosporins. It is effective against many Enterobacteriaceae such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter species, and Serratia marcescens, as noted in the guidelines for the management of intra-abdominal infections 1. Ceftazidime also has activity against some gram-positive organisms like Streptococcus pneumoniae and Streptococcus pyogenes, though its gram-positive coverage is limited compared to other cephalosporins, and it has poor activity against Staphylococcus aureus, especially methicillin-resistant strains (MRSA), and lacks coverage for anaerobes and atypical organisms 1. The most recent and highest quality study, from 2019, provides guidance on the optimization of treatment with beta-lactam antibiotics, including ceftazidime, in critically ill patients, highlighting the importance of achieving target trough total or free plasma concentrations to ensure effective treatment 1. Key points to consider when using ceftazidime include:
- Its effectiveness against Pseudomonas aeruginosa and other gram-negative bacteria
- Limited gram-positive coverage
- Poor activity against MRSA and anaerobes
- Importance of local resistance patterns and potential limitations in certain clinical settings
- Need to achieve target plasma concentrations for effective treatment, as outlined in the 2019 guidelines 1. In clinical practice, ceftazidime is often used in combination with other antibiotics to broaden its spectrum of activity, and its use should be guided by local resistance patterns and susceptibility testing, as recommended in the guidelines for the management of intra-abdominal infections 1.
From the FDA Drug Label
Ceftazidime has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section: Gram-negative bacteria • Citrobacter species • Enterobacter species • Escherichia coli • Klebsiella species • Haemophilus influenzae • Neisseria meningitidis • Proteus mirabilis • Proteus vulgaris • Pseudomonas aeruginosa • Serratia species Gram-positive bacteria • Staphylococcus aureus • Streptococcus pneumoniae • Streptococcus pyogenes • Streptococcus agalactiae Anaerobic bacteria • Bacteroides species (Note: many isolates of Bacteroides species are resistant)
Ceftazidime (ceftaz) covers a wide range of bacteria, including:
- Gram-negative bacteria:
- Citrobacter species
- Enterobacter species
- Escherichia coli
- Klebsiella species
- Haemophilus influenzae
- Neisseria meningitidis
- Proteus mirabilis
- Proteus vulgaris
- Pseudomonas aeruginosa
- Serratia species
- Gram-positive bacteria:
- Staphylococcus aureus
- Streptococcus pneumoniae
- Streptococcus pyogenes
- Streptococcus agalactiae
- Anaerobic bacteria:
- Bacteroides species (although many isolates are resistant) 2
From the Research
Bacteria Covered by Ceftazidime
Ceftazidime, also known as ceftaz, is a broad-spectrum antibiotic that covers a wide range of Gram-positive and Gram-negative bacteria. The following are some of the bacteria that ceftazidime is effective against:
- Gram-negative bacteria, including:
- Gram-positive bacteria, although it is less active against some Gram-positive cocci than other newer beta-lactam compounds 4
- Multiresistant strains of Pseudomonas aeruginosa and Enterobacteriaceae 3, 4, 5
Limitations of Ceftazidime
While ceftazidime is effective against a wide range of bacteria, it has limited activity against:
- Gram-negative anaerobes 4
- Streptococcus faecalis 4
- Methicillin-resistant Staphylococcus aureus 4
- Bacteroides fragilis, which may restrict its usage in situations where this organism is the suspected or proven pathogen 7
Clinical Applications
Ceftazidime has been shown to be effective in the treatment of various infections, including: