Methicillin sodium

Methicillin Sodium is a semi-synthetic penicillin derivative that was once widely used as an antibiotic to treat infections caused by Staphylococcus aureus bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). It is no longer in clinical use due to the prevalence of resistance.

History[edit | edit source]

Methicillin Sodium was developed by Beecham Group in the United Kingdom in 1959, in response to the need for an antibiotic that could combat penicillin-resistant Staphylococcus aureus. It was the first of the beta-lactamase-resistant penicillins to be discovered.

Mechanism of Action[edit | edit source]

Methicillin Sodium works by inhibiting the final stage of bacterial cell wall synthesis, leading to cell death. It does this by binding to and inactivating penicillin-binding proteins (PBPs) on the inner surface of the bacterial cell membrane.

Resistance[edit | edit source]

Resistance to Methicillin Sodium is primarily due to the acquisition of a new PBP, known as PBP2a, which has a low affinity for beta-lactam antibiotics. This is encoded by the mecA gene, which is carried on a mobile genetic element called the staphylococcal cassette chromosome mec (SCCmec).

Side Effects[edit | edit source]

Common side effects of Methicillin Sodium include rash, nausea, vomiting, and diarrhea. Serious side effects can include anaphylaxis, kidney failure, and neutropenia.