The oxazolidinones as a new family of antimicrobial agent

The oxazolidinones are a new chemical class of synthetic antimicrobials cha racterized by a unique mechanism of protein synthesis inhibition. Linezolid is the first compound of this class and has recently received approval for the treatment of community- and hospital-acquired pneumonia and skin and s kin structure infections. In vitro tests demonstrate that linezolid possess es a significant activity against Gram-positive pathogens including methici llin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococ ci (VR-E), vancomycin-intermediate strains (VISA) and penicillin-resistant pneumococci (PRPN). Combined with other drugs linezolid interacts favourabl y against many important pathogens and it is able to affect some bacterial virulence factors as well as produce a postantibiotic effect. Results from experimental models of infection reveal linezolid to be highly active in vivo against infections due to Gram-positive pathogens. Linezolid may be administered either intravenously or orally with. oral bio availability of approximately 100% and limited adverse effects. The clinica l efficacy of linezolid has been investigated in several phase II and III t rials. Linezolid has been proved to be useful in severe infections sustaine d by multiresistant Gram-positive microorganisms. Synthesis of the second-g eneration oxazolidinones with improved potency against Gram-positive and ne gative bacteria is currently under way.