A class of its own:
IV Fosfomycin hits hard and early

• IV Fosfomycin inhibits a first step of the bacterial cell wall synthesis ¹: The enzyme-catalyzed formation of UDP N-acetylmuramic acid through the binding of phosphoenolpyruvate and UDP-N-acetylglucosamine by Mur A
• Different from other antibiotics including β-lactams that act at a later stage and at a different site of cell wall synthesis ²
• IV Fosfomycin is actively transported into bacteria via both ubiquitous hexose monophosphate transport system (UhpT) or the L-α-glycerophosphate transport system (GlpT) ³
• Bactericidal action
• Unique structure and mechanism of action: no cross-resistance and cross-allergy

• Unique with respect to its epoxide structure and molecular weight (138 g/mol)
• No metabolization and renally excreted
• No plasma protein binding
• Higher antimicrobial activity of IV Fosfomycin under low pH and under low oxygen conditions ^{(4, 5, 6)}

1 Kahan FM, Kahan JS, Cassidy PJ, Kropp H. The mechanism of action of fosfomycin (phosphonomycin). Ann NY Acad Sci 1974; 235: 364–386
2 Falagas ME, Vouloumanou EK, Samonis G, Vardakasa KZ. Fosfomycin. Clin Microbiol Rev 2016; 29: 321–347
3 Lin EC. Glycerol dissimilation and its regulation in bacteria. Annu Rev Microbiol 1976; 30: 535–578
4 Inouye S, Watanabe T, Tsuruoka T, Kitasato I. An increase in the antimicrobial activity in vitro of fosfomycin under anaerobic conditions. J Antimicrob Chemother. 1989;24(5):657–666
5 Hirakawa H, Kurabayashi K, Tanimoto K, Tomita H. Oxygen Limitation Enhances the Antimicrobial Activity of Fosfomycin in Pseudomonas aeruginosa Following Overexpression of glpT Which Encodes Glycerol-3-Phosphate/Fosfomycin Symporter. Front Microbiol. 2018 Aug 21;9:1950. doi: 10.3389/fmicb.2018.01950. eCollection 2018
6 Martín-Gutiérrez G, Docobo-Pérez F, Rodriguez-Beltrán J, Rodríguez-Martínez JM, Aznar J, Pascual A, Blázquez J. Urinary Tract Conditions Affect Fosfomycin Activity against Escherichia coli Strains Harboring Chromosomal Mutations Involved in Fosfomycin Uptake. Antimicrob Agents Chemother. 2017 Dec 21;62(1). pii: e01899-17. doi: 10.1128/AAC.01899-17. Print 2018 Jan