Linezolid to decrease length of stay in the hospital for patients with methicillin-resistant Staphylococcus aureus infection.

Sir—An article by Stevens et al. [1], which demonstrated comparable outcomes for patients infected with methicillin-resistant Staphylococcus aureus (MRSA) who were treated with intravenously or orally administered linezolid or vancomycin, suggested that linezolid has great potential for decreasing the cost of care for patients with MRSA infection. The cost of treatment of hospitalized patients with infection is predominately determined by the length of stay (LOS) in the hospital, which, in turn, is primarily determined by the duration of intravenous antimicrobial therapy. Studies of community-acquired pneumonia, performed by our group and others, have demonstrated that patient treatment that involves an early switch from intravenously to orally administered antibiotics can save up to $3 billion per year in the United States [2, 3]. Linezolid, a member of the oxazolidinone class of antibiotics, is almost 100% orally bioavailable, whereas vancomycin can only be administered parenterally. Increasing levels of antimicrobial resistance in the United States are a major public health concern, and the incidence of MRSA infection is also increasing. Up to 64% of all nosocomial S. aureus isolates in the United States are methicillin resistant and are treated with intravenously administered vancomycin [1]. MRSA is the second most common nosocomial bloodstream isolate in the United States [4]. In a study by Abramson and Sexton [5], the median LOS in the hospital for a patient with nosocomial MRSA bloodstream infection was 12 days, with an associated median cost of $27,083 (in US$). For a similar patient group with methicillinsusceptible S. aureus (MSSA) infection, the mean LOS was 4 days, and the median associated cost was $9661 (in US$). Outpatient treatment of patients with MRSA infection has required the use of home-based or skilled nursing facility– based intravenous vancomycin therapy. The study by Stevens et al. [1] demonstrates that linezolid is as efficacious as vancomycin for the treatment of a variety of MRSA infections. Patients with MRSA infection could be treated initially with intravenously administered linezolid or vancomycin in the hospital, and then the transition to oral therapy with linezolid tablets could be made rapidly. If one extrapolates from the study of MRSA and MSSA by Abramson and Sexton [5], there appears to be a potential savings of $17,000 (in US$) per patient if the MRSA-infected patient is able to leave the hospital after 4 days, as did the MSSA-infected patient [5]. In another study of patients treated for MRSA infection, an intention-to-treat analysis demonstrated a reduction of 4 days in the adjusted LOS when linezolid, rather than vancomycin, was administered to patients considered to be in the 25th percentile group for LOS [6]. Studies need to be conducted to demonstrate that the practice of switching from intravenous to oral linezolid is safe and that it has an associated efficacy equal to that of treatment with intravenous linezolid only. However, as long as the gastrointestinal tract is functioning normally, this approach to care has the potential to revolutionize the treatment of MRSA, just as early switching from oral to intravenous therapy has revolutionized the treatment of community-acquired pneumonia. Robert E. Siegel Critical Care Center, Bronx Veterans Affairs Medical Center, Bronx, and Mount Sinai School of Medicine, New York, New York