Ceftazidime is a bactericidal cephalosporin antibiotic that works by inhibiting bacterial cell wall synthesis. It is effective against a broad spectrum of Gram-positive and Gram-negative bacteria, tolerates most beta-lactamases, and is also effective against strains resistant to gentamicin and other aminoglycosides. In vitro, ceftazidime is effective against a variety of Gram-negative bacteria (such as Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, etc.), Gram-positive bacteria (such as Staphylococcus aureus, Streptococcus, etc.) and some anaerobic bacteria, but has no effect on methicillin-resistant Staphylococci, Enterococcus faecalis, etc. When used in combination with aminoglycoside antibiotics, the efficacy is at least additive, and in some cases it has a synergistic effect.

Not described in detail

The second-generation cephalosporin antibiotics are rapidly hydrolyzed into cefuroxime after entering the body. They have strong antibacterial effects on most Gram-positive cocci, and have good effects on Corynebacterium diphtheriae and Gram-positive anaerobic bacteria. They are highly active against Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae and Haemophilus influenzae. They are sensitive to Salmonella typhi, Shigella, Neisseria gonorrhoeae and Neisseria meningitidis, but have poor antibacterial effects on Bacteroides fragilis. They bind to penicillin-binding proteins (PBPs) on the bacterial cell membrane, inhibit the synthesis of the bacterial septum and cell wall, and cause bacterial dissolution and death.

This product belongs to the third generation of cephalosporin, with a broad-spectrum antibacterial effect, and is stable against broad-spectrum β-lactamases (including penicillinase and cephalosporinase) produced by various Gram-positive and Gram-negative bacteria. This product has a strong antibacterial effect on Enterobacteriaceae such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Pseudomonas and Acinetobacter species such as Pseudomonas aeruginosa are less sensitive to this product. Ceftizoxime has a good antibacterial effect on Haemophilus influenzae and Neisseria gonorrhoeae. This product has a poorer effect on Staphylococcus aureus and Staphylococcus epidermidis than the first and second generation cephalosporins. Methicillin-resistant Staphylococcus aureus and Enterococcus are resistant to this product, and various streptococci are highly sensitive to this product. Anaerobic bacteria such as Peptococcus, Peptostreptococcus and some Bacteroides are mostly sensitive to this product, and Clostridium difficile is resistant to this product. The mechanism of action of this product is that this product achieves a bactericidal effect by inhibiting the biosynthesis of bacterial cell wall mucopeptides.

Cefixime is a third-generation oral cephalosporin that kills bacteria by inhibiting bacterial cell wall synthesis. It is stable to most β-lactamases, and many strains producing penicillinase and cephalosporinase are still sensitive to this product. Cefixime has good antibacterial effects in vitro and in vivo against Gram-positive cocci such as pneumococci, Streptococcus pyogenes, and Gram-negative bacilli such as Haemophilus influenzae (including enzyme-producing strains), Moraxella catarrhalis (including enzyme-producing strains), Escherichia coli, Proteus mirabilis, and Neisseria gonorrhoeae (including enzyme-producing strains). Cefixime also has antibacterial activity against Streptococcus pneumoniae, Parainfluenzae, Proteus vulgaris, Klebsiella pneumoniae, Pasteurella multocida, Providencia, Salmonella, Shigella, Serratia marcescens, Citrobacter heteromorphis, and Citrobacter malonate, but its clinical effectiveness has not yet been established. This product has poor antibacterial effect on Staphylococcus, and has no antibacterial effect on Pseudomonas aeruginosa, Enterobacter, Bacteroides fragilis, Clostridium, etc.