TY - CHAP M1 - Book, Section TI - Other Beta-Lactam Medications A1 - Gruenberg, Katherine A1 - Guglielmo, B. Joseph A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. A2 - McQuaid, Kenneth R. PY - 2023 T2 - Current Medical Diagnosis & Treatment 2023 AB - Aztreonam is the sole marketed monobactam, so named due its monocyclic beta-lactam ring resistant to many beta-lactamases. Aztreonam is active against gram-negative organisms (including Pseudomonas) but has no activity against gram-positive organisms or anaerobes. Aztreonam resembles ceftazidime with its gram-negative activity. Thus, it is generally strong against E coli, Klebsiella, Proteus, and Pseudomonas spp, but its activity is unpredictable against Acinetobacter, Enterobacter, and Citrobacter spp. Clinical uses of aztreonam are limited because of the availability of third-generation cephalosporins with a broader spectrum of activity and minimal toxicity. However, the clinical role of aztreonam may expand; it is being investigated in combination with the beta-lactamase inhibitor avibactam for the management of metallo-beta-lactamase–producing Enterobacteriaceae (eg, E coli, Klebsiella, Proteus), for which few other therapies are available. Considering its activity against P aeruginosa, aztreonam is also useful in the management of patients with cystic fibrosis as an inhaled dose of 75 mg administered three times daily. Despite the structural similarity of aztreonam to penicillin, IgE cross-reactivity does not exist, and it can therefore be used in patients with IgE-mediated penicillin allergy. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1193121991 ER -