β-lactamase inhibitors are often given in combination with penicillins to tackle the problem of the resistance caused by the presence of β-lactamases from bacterial cells.  An example is Co-Amoxiclav [Augmentin], which is a combination of amoxicillin [a semi-synthetic penicillin, R = CH(NH2)(C6H6OH)] and clavulanic acid [a β-lactamase inhibitor].  Two other β-lactamase inhibitors are sulbactam and tazobactam.  The mechanism of action of clavulanic acid is shown below.8

Clavulanic acid inhibits the β-lactamase enzyme by binding to a serine residue in the active site.  Clavulanic acid does not have any antibacterial properties of its own, but by irreversibly binding to the β-lactamase molecules present, it allows the penicillin to attack the peptidoglycan cell wall in order to destroy the bacterial cell.8