NCIt definition : The sodium salt form of benzylpenicillin, a semi-synthetic, broad-spectrum penicillin
antibiotic with bactericidal activity. Benzylpenicillin sodium 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-linkage 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.;