methicillin

A synthetic antibiotic related to penicillin, C₁₇H₁₉N₂O₆NaS, used to treat infections caused by staphylococci that produce beta-lactamase and are therefore resistant to beta-lactam penicillin drugs. It has largely been replaced by newer synthetic penicillin drugs that act similarly, such as dicloxacillin.

An antibiotic drug, chemically related to penicillin, often used against strains of bacteria which have become resistant to penicillin.

antibiotic drug of the penicillin family used in the treatment of certain staphylococcal infections