Oxacillin Injection

Category: Beta-lactam antibiotic (Penicillin class, penicillinase-resistant)
Form: Injectable solution for intravenous (IV) or intramuscular (IM) use

Uses:

• Treatment of infections caused by penicillinase-producing Staphylococcus aureus.

• Effective for:

  • Skin and soft tissue infections

  • Bone and joint infections (osteomyelitis, septic arthritis)

  • Respiratory tract infections

  • Endocarditis caused by susceptible bacteria

• Not effective against methicillin-resistant Staphylococcus aureus (MRSA) or penicillin-resistant bacteria.

Mechanism of Action:

• Oxacillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs).

• This leads to cell lysis and death of actively dividing bacteria.

• Resistant to degradation by staphylococcal penicillinase, unlike regular penicillin.

Administration:

• Intravenous or intramuscular injection, usually every 4–6 hours depending on infection severity.

• Dosage is adjusted based on patient weight, kidney function, and type of infection.

Side Effects:

• Gastrointestinal: nausea, vomiting, diarrhea.

• Allergic reactions: rash, urticaria, rare anaphylaxis.

• Hematologic: neutropenia, eosinophilia (rare with prolonged use).

• Local reactions: pain or inflammation at injection site.

• Liver: transient elevation of liver enzymes (rare).

Precautions:

• Assess for penicillin allergy before administration.

• Use cautiously in patients with kidney or liver impairment.

• Monitor for signs of superinfection during prolonged therapy.

Summary:
Oxacillin Injection is a penicillinase-resistant antibiotic used to treat staphylococcal infections. It works by disrupting bacterial cell wall synthesis, leading to bacterial death. It is administered intravenously or intramuscularly, with common side effects including gastrointestinal upset, allergic reactions, and injection site irritation. Careful monitoring is required in allergic patients and those with renal or hepatic issues.