First generation cephalosporines
Most active against S. aureus, Group A Beta-hemolytic streptococci, and Pneumococcus.
Effective against Pseudomas aeruginosa.
Have the broadest spectrum of activity of all cephalosporins and are extremely effective against gram-negative organisms. They are more active against E.coli, Klebsiella pneumoniae, Enterobacter, Salmonella. and Shigella.
Still have efficacy against gram-postivie organisms but also possess good activity against E. coli and H. influenzae.