Methicillin-ResistantStaphylococcus aureusInfections

Abstract

To the Editor: In his review of skin and softtissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA), Daum (July 26 issue)1 cites a study2 indicating that intravenous trimethoprim–sulfamethoxazole (TMP-SMX) is significantly less effective than vancomycin for the treatment of serious S. aureus infections. However, in this randomized, double-blind, comparative trial of TMP-SMX and vancomycin, therapeutic failures occurred only in patients with methicillin-susceptible S. aureus (MSSA) infections. TMP-SMX was successful in treating all MRSA infections, including tricuspid-valve endocarditis. Clinical failures commonly occurred with MSSA tricuspid-valve endocarditis; otherwise, the cure rates with TMPSMX and with vancomycin were similar. On the basis of the results of this study, vancomycin may be superior for MSSA infections; however, the same cannot be concluded for MRSA infections. Although the currently available clinical data for community-associated MRSA skin infections are sparse, in this era of an increasing incidence of MRSA infection and concern about the variable efficacy of vancomycin, TMP-SMX may be a useful alternative in selected cases.