Meticillin

Meticillin (INN, BAN) or methicillin (USAN, AAN) is a narrow-spectrum β-lactam antibiotic of the penicillin class. It should not be confused with the antibiotic metacycline. In 2005, the name of the drug was changed from methicillin to meticillin in accordance with the International Pharmacopoeia guidelines.

History

Meticillin was developed by Beecham in 1959. It was previously used to treat infections caused by susceptible Gram-positive bacteria, in particular, penicillinase-producing organisms such as Staphylococcus aureus that would otherwise be resistant to most penicillins.

Its role in therapy has been largely replaced by flucloxacillin and dicloxacillin, but the term meticillin-resistant Staphylococcus aureus (MRSA) continues to be used to describe S. aureus strains resistant to all penicillins.

Meticillin is no longer manufactured because the more stable and similar penicillins such as oxacillin (used for clinical antimicrobial susceptibility testing), flucloxacillin, and dicloxacillin are used medically.