Contains β-lactam ring with same mechanism as PCNs; 10% cross-reactivity with PCNs
Spectrum of bacterial coverage based upon generation of cephalosporin:
First generation: GP > gram-negative (GN); second generation: GP = GN; third generation: GP < GN; fourth generation: GP, GN (little activity against β-lactamase)
Adverse effects: AGEP, morbilliform eruption (serum sickness associated with cefaclor)
