NCIt definition : The hydrochloride salt form of a semisynthetic, orally active pivalate ester of ampicillin
with antibacterial activity. Upon absorption, pivampicillin is hydrolyzed into its
active form ampicillin by esterases. Ampicillin binds to and inactivates penicillin-binding
proteins (PBPs) 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 interrupts bacterial cell wall synthesis and
results in the weakening of the bacterial cell wall, eventually causing cell lysis.;