Linezolid - A synthetic oxazolidinone antimicrobial for treatment of serious gram-positive infections

Linezolid is the first in a new class of antimicrobials called oxazolidinon es. It is the first agent since vancomycin to be approved with a specific i ndication for methicillin-resistant Staphylococcus aureus (MRSA) infections . Linezolid possesses a unique mechanism of action that accounts for its ef fectiveness in multidrug-resistant gram-positive infections. II disrupts pr otein synthesis of gram-positive bacteria by binding to the 503 ribosomal s ubunit and inhibiting formation of the 70S initiation complex. Phase III tr ials have shown linezolid to be effective in the treatment of infections ca used by vancomycin-resistant Enterococcus faecium and hospital-acquired pne umonia, including cases caused by MRSA, Linezolid is well tolerated, with h eadache, nausea, and diarrhea being the most common adverse effects. The dr ug's 5-hour elimination half-life and short postantibiotic effect allow twi ce-daily dosing. Availability of both intravenous and oral formulations all ows for "IV to PO" switching without the need for dosage or antimicrobial c hanges.