NEW BETA-LACTAM ANTIBIOTICS IN CRITICAL CARE MEDICINE

Aztreonam, imipenem, and several third-generation cephalosporins are new beta-lactam antibiotics widely used in human critical care facilities. These agents are increasingly used in veterinary critical care units for treating infections caused by bacterial species that are otherwise resistant to antibiotic counteragents. Although imipenem has a broad antibacterial spectrum, which includes gram-positive and gram-negative aerobes and anaerobes, some new beta-lactam agents (such as aztreonam) have more specific uses and must be carefully administered. Third-generation cephalosporins offer a wider spectrum of use than first- and second-generation cephalosporins but are most effective when used in precarious cases involving gram-negative infections. Because veterinary use of these new antibiotics is in its genesis, clinicians must proceed carefully, using available data on dosing in humans. The clinical pharmacology and therapeutic uses of the new agents are reviewed in this article.