Cefoxitin, a semi-synthetic cephamycin: a microbiological overview

Cefoxitin is a chemically modified form of a member of a new family of β-lactam antibiotics, the cephamycins. Cefoxitin resembles the cephalosporins, but due to its 7α-methoxyl group (a unique structural feature of the cephamycin family), it possesses important biochemical characteristics not found in other β-lactam antibiotics. The methoxyl group provides the molecule with a remarkable degree of resistance to all β-lactamases. This resistance provides the antibiotic with a broad antibacterial spectrum, including activity against indole-positive Proteus strains, Serratia spp. and Bacteroides spp. (including Bacteroides fragilis and all its subspecies) as well as against all the bacterial pathogens normally sensitive to the cephalosporins. In addition, cefoxitin is active against many strains of Gram-negative bacteria that have become refractory to other β-lactam antibiotics. Cefoxitin is a cell-wall-active agent and is bactericidal in its action. Marked resistance to enzymatic degradation, high bactericidal activity over a large range of inoculum levels, and favorable metabolic disposition makes cefoxitin a highly effective agent in vivo. Thus, cefoxitin is a major advance over other β-lactam antibiotics in current use.