Cephalosporin: Classification by Generation-
Classification by Generation (This classification is based on general features of antimicrobial activity).
1st Generation: Cephradine, Cephalexin, Cefadroxil
Good activity against gram-positive bacteria and relatively modest activity against gram-negative bacteria.
2nd Generation: Cefaclor, Cefuroxime
Somewhat increased activity against gram-negative bacteria but are much less active than the third-generation agents.
3rd Generation: Cefixime, Ceftriaxone, Cefpodoxime, Ceftazidime
Generally are less active than 1st generation agents against gram-positive cocci, but they are much active against the Enterobacteriaceae, including the B-lactamase producing strains.
4th Generation: Cefepime, Cefpirome
Extended-spectrum of activity compared to the third generation and have increased stability from hydrolysis by Beta lactamases. Fourth-generation agents prove to have particular therapeutic usefulness in the treatment of infections due to aerobic gram-negative bacilli resistant to third-generation cephalosporins.