Oxacillin is a type of antibiotic that belongs to the penicillin group. It is primarily used to treat infections caused by certain bacteria, particularly those that are resistant to other penicillins. Oxacillin works by inhibiting the growth of bacteria, making it effective against infections like skin infections, pneumonia, and some types of bloodstream infections. This medication is often administered through an injection or intravenously in a hospital setting. It is important to use Oxacillin as prescribed by a healthcare professional to ensure its effectiveness and to reduce the risk of antibiotic resistance. Common side effects may include allergic reactions, gastrointestinal issues, and changes in liver function.