Cloxacillin is an isoxazolyl penicillin used primarily for the treatment of infections due to staphylococci resistant to benzylpenicillin, including infections of the skin and soft tissues, bones and joints, respiratory tract and urinary tract; otitis media, endocarditis, septicemia and meningitis. It is also used for mixed streptococcal infections when the staphylococci are penicillin resistant. It is also used for the prophylaxis of staphylococcal infections during major procedures, particularly in the cardiothoracic and orthopedic surgery.