Trimethoprim-sulfamethoxazole as a viable treatment option for infections caused by methicillin-resistant Staphylococcus aureus.
OBJECTIVE
To review available data regarding the efficacy of trimethoprim-sulfamethoxazole (TMP-SMX) for the treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA).


METHODS
A MEDLINE search was performed (January 1966-December 2003) using the search terms Staphylococcus aureus , sulfamethoxazole, trimethoprim, co-trimoxazole, and methicillin resistance. Abstracts from infectious diseases meetings also were reviewed.


RESULTS
The reported rate of TMP-SMX resistance in S. aureus is highly variable. From a mechanistic standpoint, TMP-SMX resistance among MRSA appears to be distinct from multidrug resistance, although some anecdotal reports suggest otherwise. Clonal outbreaks of MRSA resistant to TMP-SMX have been described; of these, the Brazilian clone has more often been resistant to TMP-SMX than the Iberian clone. Rates of TMP-SMX resistance are particularly high in institutions serving large numbers of patients infected by the human immunodeficiency virus, due to increased exposure for Pneumocystis prophylaxis. Limited studies and case reports have found TMP-SMX useful against infections caused by MRSA.


CONCLUSIONS
A large body of anecdotal data, but only one randomized clinical trial, indicates the effectiveness of TMP-SMX as a treatment for MRSA infections. Double-blind, randomized controlled trials are needed to compare the two available oral agents-TMP-SMX and linezolid-against MRSA.
Grim
Shellee A
SA
Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA. sgrim@uic.edu
Rapp
Robert P
RP
Martin
Craig A
CA
Evans
Martin E
ME
D000890:Anti-Infective Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004347:Drug Interactions; D006207:Half-Life; D006801:Humans; D016106:Methicillin Resistance / Q000187:drug effects; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects*; D014018:Tissue Distribution; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*
D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination