Cefotetan is a semi-synthetic second-generation cephamycin antibiotic with [(1-methyl-1H-tetrazol-5-yl)sulfanyl]methyl, methoxy and {[4-(2-amino-1-carboxy-2-oxoethylidene)-1,3-dithietan-2-yl]carbonyl}amino groups at the 3, 7alpha, and 7beta positions, respectively, of the cephem skeleton. It is resistant to a wide range of beta-lactamases and is active against a broad spectrum of aerobic and anaerobic Gram-positive and Gram-negative microorganisms. It has a role as an antibacterial drug. It is a conjugate acid of a cefotetan(2-).