Source:http://linkedlifedata.com/resource/umls/id/C0887175
NCI: The sodium salt form of methicillin, a semisynthetic beta-lactam penicillin antibiotic with beta-lactamase resistant activity. Methicillin sodium is bactericidal and binds to specific penicillin-binding proteins on the bacterium and inhibits the transpeptidation enzyme, thereby preventing the cross-linking of peptidoglycans. This leads to an interruption of the bacterial cell wall and causes bacterial lysis. Methicillin sodium is active against beta-lactamase producing staphylococci.