NCIt definition : A beta-lactam, first-generation cephalosporin antibiotic with bactericidal activity.
Cephalexin binds to and inactivates penicillin-binding proteins (PBP) located on the
inner membrane of the bacterial cell wall. Inactivation of PBPs interferes with the
cross-linking of peptidoglycan chains necessary for bacterial cell wall strength and
rigidity. This results in the weakening of the bacterial cell wall and causes cell
lysis. Compared to second and third generation cephalosporins, cephalexin is more
active against gram-positive and less active against gram-negative organisms.;
Alternative definition : NCI-GLOSS: An antibiotic drug that belongs to the family of drugs called cephalosporins.;