NCIt definition : A naphthydridine derivative of the broad spectrum, semisynthetic ampicillin with antibacterial
activity. Apalcillin specifically binds to and inactivates penicillin-binding proteins
(PBPs) located on the inner membrane of the bacterial cell wall, thereby preventing
the cross-linkage of peptidoglycans, which are critical components of the bacterial
cell wall. This leads to a weakening of the bacterial cell wall, eventually causing
bacterial cell lysis.;