Antimicrobial Agents in Treatment of MRSA Infections

One-year mortality rates among patients with MRSA SSTI have been reported as high as 22%, and up to 33% of MRSA bacteremia proved fatal during hospitalization, emphasizing the critical importance of early appropriate empiric therapy.³⁹ Because strains tend to be multidrug resistant, therapeutic options are limited, and current local antimicrobial resistance patterns should be taken into consideration in treatment decisions. Resistance and drug intolerance further limit options, and concerns about expense and total dose dependent myelosuppression toxicities persist for linezolid. Furthermore, in addition to the overwhelming emergence of CA-MRSA, glycopeptide resistance and decreasing susceptibility ("MIC creep") in vancomycin-susceptible strains has progressively limited the previously reliable use of vancomycin. In the near future, as new parental therapies continue to be available for severe infection, two ongoing NIH-funded clinical trials in the U.S. will provide insight on effectiveness of oral antimicrobial agents for CA-MRSA SSTI, and new treatment guidelines will be available in Fall 2008.³.