Aztreonam-d6 is intended for use as an internal standard for the quantification of aztreonam by GC- or LC-MS. Aztreonam is a synthetic β-lactam antibiotic of the monobactam class.1 It is active against clinical isolates of E. coli, S. marcescens, P. aeruginosa, Klebsiella species, Proteus species, and Enterobacter species (MICs = <0.1, 1.2, 5.2, 3.1, <0.1, and 19.3 μg/ml, respectively) but is inactive against S. pneumoniae, B. fragilis, and S. faecalis (MICs = >100 μg/ml for all). It interferes with peptidoglycan synthesis in the bacterial cell wall of the Gram-negative bacteria E. coli, P. vulgaris, E. cloacae, K. pneumoniae, and P. aeruginosa by inhibiting penicillin-binding protein 3 (PBP3; IC100 = 0.1 μg/ml for all). It increases survival in mice with systemic Gram-negative bacterial infections (ED50s = 0.1-24.7 mg/kg). Formulations containing aztreonam have been used in the treatment of P. aeruginosa infections in individuals with cystic fibrosis.

|1. Sykes, R.B., Bonner, D.P., Bush, K., et al. Azthreonam (SQ 26,776), a synthetic monobactam specifically active against aerobic gram-negative bacteria. Antimicrob. Agents Chemother. 21(1), 85-92 (1982).