Used primarily as an injectable antibiotic to treat infections caused by penicillinase-producing staphylococci, including skin and soft tissue infections, respiratory tract infections, and bone and joint infections. It is particularly effective in hospital settings where resistant bacterial strains are common. Due to its beta-lactamase resistance, it remains active against bacteria that inactivate other penicillins. Often administered intravenously or intramuscularly for serious infections, especially in patients with confirmed or suspected gram-positive bacterial involvement.