In the October 2006 issue of the Archives, Hidayat et al1 addressed an alarming issue related to vancomycin treatment failures for infections caused by vancomycin-susceptible MRSA strains with a relatively high MIC. They suggested the use of combination or alternative therapy for invasive infections.
In fact, the pertinent issue is relevant to alternative therapy. Should we use newer agents or should we go back and reexamine the efficacy of older therapies against MRSA? We might suggest an answer with reference to our clinical findings published 13 years ago by Jemni et al.2 In this series, 26 of 27 patients treated with trimethoprim-sulfamethoxazole for MRSA infections were cured. Newer antistaphylococcal agents certainly have a proven efficacy but are not routinely prescribed. In addition, resistance to quinupristin-dalfopristin and linezolid has emerged.3 Therefore, it is justified to reexamine the clinical efficacy of older therapies active against MRSA. This is particularly interesting because of the recent proliferation of community-acquired MRSA and the consequent marked increase in the need of outpatient treatment of MRSA infections. A recent comparative study on bactericidal activity of orally available agents against MRSA concluded that trimethoprim-sulfamethoxazole is rapidly bactericidal against MRSA in vitro compared with most other orally available antimicrobials.4 Since the early 1970s, the efficacy of trimethoprim-sulfamethoxazole in severe S aureus infections has been reported.5 We believe that the widespread and inappropriate use of vancomycin may have contributed to the emergence of vancomycin-intermediate S aureus and vancomycin-resistant S aureus. The rise in MRSA prevalence will continue to drive not only the increase in empirical use of vancomycin but also aggressive empirical vancomycin dosing. Therefore, returning to older molecules and assessing their clinical efficacy seems to be a reasonable option for investigation.
Hmouda H, Ben Salem C, Bouraoui K, Jemni L. Treatment of MRSA Infections With Older Molecules: A Reasonable Option for Investigation. Arch Intern Med. 2007;167(11):1207-1208. doi:10.1001/archinte.167.11.1207-b