Vancomycin versus linezolid in the treatment of methicillin-resistant Staphylococcus aureus nosocomial pneumonia: implications of the ZEPHyR trial.

In 2003, a retrospective trial comparing linezolid versus vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) showed improved survival in the linezolid group. This led to the ZEPHyR (Linezolid in the Treatment of Subjects with Nosocomial Pneumonia Proven to Be Due to Methicillin-Resistant Staphylococcus aureus) trial comparing linezolid versus vancomycin for MRSA pneumonia, which showed a benefit for linezolid with respect to clinical response but without a survival advantage. Limitations of the study included unbalanced treatment groups at baseline and number of patients excluded to reach the per-protocol group. Results of the ZEPHyR trial do not support routine use of linezolid for the treatment of MRSA pneumonia.