Cefoxitin is a cephamycin antibiotic often grouped with the second−generation cephalosporins. Cefoxitin acts by interfering with cell wall synthesis. Its activity spectrum includes a broad range of gram-negative and gram-positive bacteria including anaerobes. It is inactive in vitro to most strains of Pseudomonas aeruginosa and many strains of Enterobacter cloacae. Staphylococci resistant to methicillin/oxacillin should be considered resistant to cefoxitin. Cefoxitin is considered to be a strong beta-lactamase inducer, as are certain other antibiotics (such as imipenem). Cefoxitin has a broad spectrum of activity and has been used in the treatment of skin, bone, respiratory and urinary tract infections. Susceptible bacteria include some Staphylococci, Enterococci, Streptococci, and others. The following represents MIC susceptibility data for a few medically significant microorganisms.