Ampicillin-Cloxacillin is a combination antibiotic containing two penicillin-class agents: ampicillin, which is effective against a broad range of bacteria, and cloxacillin, which is particularly effective against penicillinase-producing staphylococci. This combination is used to treat a variety of bacterial infections, including respiratory tract infections, skin and soft tissue infections, and urinary tract infections. It works by inhibiting bacterial cell wall synthesis, leading to the elimination of susceptible bacteria.