- methicillin
- meth·i·cil·lin .meth-ə-'sil-ən n a semisynthetic penicillin C17H19N2O6NaS that is esp. effective against beta-lactamase producing staphylococci
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n.a semisynthetic penicillin that was originally used to treat infections by penicillin-resistant staphylococci. It has been superseded for this purpose by flucloxacillin but continues to be used to test the drug sensitivity of staphylococci. Methicillin-resistant staphylococci (MRS) can be responsible for increasing rates of infection in hospitals. Until recently, such infections have responded to vancomycin, but strains of bacilli have started to emerge that are resistant to both methicillin and vancomycin, giving rise to infections that are very difficult to treat. See also superinfection.
Medical dictionary. 2011.