clavulanic acid

A semi-synthetic β-lactamase inhibitor produced by strains of Streptomyces clavuligerus.

It contains a β-lactam ring and binds strongly to β-lactamase at or near its active site, thereby hindering enzymatic activity. This protects other β-lactam antibiotics from β-lactamase catalysis, thereby enhancing their antibacterial effects.

It is used in conjunction with β-lactamase susceptible antibiotics (e.g. penicillins and cephalosporins) to treat infections caused by β-lactamase producing organisms.
As it is not effective by itself as an antibiotic, it is used as combined with penicillin-group antibiotics (e.g. amoxicillin, ticarcillin).

It can overcome antibiotic resistance in bacteria that secrete β-lactamase, which otherwise inactivates most penicillins (e.g. Pseudomonas, Serratia, Enterobacter, Staphylococcus, Streptococcus, Haemophilus influenzae, Meningococcus, Neisseria gonorrhoeae).