Cloxacillin Sodium Salt Monohydrate

Cloxacillin sodium, an isoxazolyl penicillin, is chemically synthesized from 6-APA [A0800]. Cloxacillin has activity against Gram-positive bacteria, but less activity against Gram-negative bacteria, the same as penicillin G [P1770] [P1772]. It acts as a competitive inhibitor of the enzyme transpeptidase, which is needed by bacteria to make their cell walls. Meanwhile, cloxacillin, oxacillin [O0353] and methicillin are resistant to the enzymes (β-lactamases) which produced by bacteria that destroy β-lactam antibiotics like penicillins and cephalosporins, due to theirs large side-chain, which does not allow the β-lactamases to bind. However, with the widespread use of cloxacillin, antibiotic-resistant strains called cloxacillin-resistant Staphylococcus aureus have become increasingly prevalent worldwide.