Cefalotin is a semisynthetic, first-generation cephalosporin antibiotic with acetoxymethyl and (2-thienylacetyl)nitrilo moieties at positions 3 and 7, respectively, of the core structure. Administered parenterally during surgery and to treat a wide spectrum of blood infections. It has a role as an antimicrobial agent and an antibacterial drug. It is a semisynthetic derivative, a beta-lactam antibiotic allergen, a cephalosporin, a carboxylic acid, a member of thiophenes and an azabicycloalkene. It is a conjugate acid of a cefalotin(1-).