monobaktams

Monobactams are a class of synthetic beta-lactam antibiotics. Unlike penicillin and cephalosporins which have a fused ring structure, monobactams possess a single beta-lactam ring. The most well-known and clinically used monobactam is aztreonam. These antibiotics are primarily active against aerobic Gram-negative bacteria. They exert their antibacterial effect by inhibiting bacterial cell wall synthesis. Specifically, they bind to and inactivate penicillin-binding proteins (PBPs), particularly PBP-3, which are essential for the elongation of the bacterial cell. This disruption leads to cell lysis. Monobactams are typically administered intravenously or intramuscularly. They are often used in cases of serious infections caused by susceptible Gram-negative organisms, especially in patients with allergies to penicillin or cephalosporins, as they have a low cross-reactivity with these other beta-lactam classes. Aztreonam is generally well-tolerated, with common side effects including rash and gastrointestinal disturbances. Resistance to monobactams can occur through the production of beta-lactamases, enzymes that hydrolyze the beta-lactam ring, or through alterations in PBPs. Their spectrum of activity makes them a valuable option in specific clinical scenarios.