Flucloxacillin is a semisynthetic isoxazolyl penicillin antibiotic primarily used in the treatment of infections caused by penicillinase-producing Staphylococcus aureus, including skin, soft tissue, bone, and joint infections. It exerts its antibacterial effect by inhibiting bacterial cell wall synthesis through binding to penicillin-binding proteins, leading to cell lysis. Historically, flucloxacillin was developed in the late 1950s and early 1960s following the emergence of penicillin-resistant staphylococci, as part of efforts to modify the penicillin nucleus to resist β-lactamase degradation. Introduced after earlier agents such as methicillin and cloxacillin, flucloxacillin demonstrated improved oral stability and effectiveness, leading to its widespread adoption, particularly in Europe and other regions. Over time, it has remained an important first-line therapy for susceptible staphylococcal infections, with its clinical use shaped by ongoing monitoring of resistance patterns and antimicrobial stewardship practices.
