First-Generation Cephalosporins:
[[Cefalothin]] (injection, oral)
[[Cefalexin]] (oral)
[[Cefazolin]]
Narrow spectrum: mainly effective against G+ cocci, weak against G- bacilli, ineffective against Pseudomonas aeruginosa, anaerobes, and resistant Enterobacteriaceae
Features: stable against penicillinase, can be destroyed by β-lactamase produced by most Gram-negative bacteria, nephrotoxic
Second-Generation Cephalosporins (Commonly Used)
[[Cefuroxime]]
[[Cefaclor]] (oral)
[[Cefoxitin]]
[[Cefprozil]], [[Cefmandole]]…
Antimicrobial spectrum: similar, stronger activity against Gram-negative bacteria than first generation
Features: less nephrotoxic than first generation
Third-Generation Cephalosporins (Commonly Used)
[[Cefotaxime]]
[[Ceftriaxone]], [[Cefoperazone]] mainly eliminated via hepatic bile
[[Cefdinir]], [[Cefixime]]…
Broad spectrum: lower activity against Gram-positive bacteria than first and second generations, stronger activity against Gram-negative bacteria than first and second generations, effective against Pseudomonas aeruginosa and anaerobes.
Mainly used to treat serious infections caused by resistant bacteria or pathogens dominated by G- bacilli, often with mixed anaerobic and G+ bacterial infection
Features: stable against most β-lactamases, can be decomposed by extended-spectrum β-lactamases, basically no nephrotoxicity.
Fourth-Generation Cephalosporins
[[Cefpirome]], [[Cefepime]]…
Broad spectrum: ineffective against [[MRSA]], effective against Gram-negative bacilli resistant to third-generation cephalosporins, good antimicrobial effect against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and anaerobes.
Application: mainly used for severe infections caused by third-generation resistant G- bacilli
Features: highly enzyme stable, no nephrotoxicity
Fifth-Generation Cephalosporins
[[Ceftobiprole]], [[Ceftaroline fosamil]], [[Ceftobiprole]]…
Antimicrobial spectrum: broad spectrum
Effective against MRSA and multidrug-resistant Streptococcus pneumoniae, weaker against Gram-negative bacteria such as Pseudomonas aeruginosa.
Features: stable against most β-lactamases, can be decomposed by extended-spectrum β-lactamases or metallo-β-lactamases, no nephrotoxicity
Comparison of Fifth-Generation Cephalosporins
Nephrotoxicity
Fifth generation = Fourth generation < Third < Second < First
| Generation | Anti-G+ | Anti-G- | Stability to β-lactamase | |
|---|---|---|---|---|
| First | +++ | + | + | Mainly used for skin infections (mainly G+ Staphylococcus aureus) |
| Second | ++ | ++ | ++ | Oral administration |
| Third | + | +++ | +++ | |
| Fourth | ++ | +++ | ++++ |