Flucloxacillin sodium is primarily used to treat bacterial infections caused by susceptible, penicillin-resistant staphylococci. It is especially effective in treating skin and soft tissue infections such as boils, cellulitis, and wound infections. Due to its resistance to breakdown by bacterial enzymes like beta-lactamase, it remains active against many strains of Staphylococcus aureus that produce these enzymes. It is also used in the management of respiratory tract infections, bone infections like osteomyelitis, and joint infections such as septic arthritis when caused by sensitive organisms. Flucloxacillin sodium can be administered orally or by injection, making it suitable for both outpatient and hospital settings. In surgical prophylaxis, it is sometimes given before procedures involving high-risk implants to prevent staphylococcal infections. Its narrow spectrum helps preserve normal flora compared to broader antibiotics, reducing the risk of secondary infections.