Have the oxazolidinones lived up to their billing? Future perspectives for this antibacterial class.

Linezolid was the first antibacterial oxazolidinone to be approved for clinical use. Oxazolidinones meet a growing medical need to treat multidrug-resistant, methicillin-resistant staphylococci, vancomycin-resistant enterococci, and penicillin-non-susceptible pneumococci in hospitalized patients. They also offer a treatment option for patients who are intolerant of vancomycin and other antibacterial agents, or who have infections that are refractory or resistant to other therapies. Two main concerns, however, have arisen as linezolid use has increased. The first is the incidence of myelosuppression, in particular thrombocytopenia, which appears to be greater than that seen during clinical trials. Secondly, linezolid-resistant Staphylococcus aureus and enterococci have emerged during linezolid treatment, which can be transmitted from patient-to-patient. This review will discuss the mechanism of action, the mechanism of resistance, and the antibacterial spectrum and potency of the oxazolidinones. In addition, the efficacy and safety of linezolid derived from clinical experience will be presented.