Correspondence
Therapy for Methicillin-Resistant Staphylococcus aureus
N Engl J Med 2006; 355:2153-2155November 16, 2006
- Article
To the Editor:
In the study by Fowler et al. (Aug. 17 issue),1 the standard therapy for Staphylococcus aureus infection is not a homogeneous entity. One cannot compare a new drug (daptomycin) with a mixture of two regimens (vancomycin or an antistaphylococcal penicillin) when the first regimen is reported to be considerably inferior to the other.2,3 Although Table 2 of the article lists success rates according to the susceptibility of S. aureus to methicillin, a breakdown in success rates according to the receipt of vancomycin or an antistaphylococcal penicillin is lacking. Patients with methicillin-susceptible S. aureus (MSSA) infections could have received vancomycin for a variety of reasons, thus blurring the possible difference in outcomes between the two regimens. The authors should analyze the outcomes separately for patients who received vancomycin and for patients who received an antistaphylococcal penicillin. Daptomycin may prove to be inferior to the highly effective antistaphylococcal penicillins, and such information should be disclosed appropriately.
3 ReferencesYardena Siegman-Igra, M.D.
Tel Aviv Sourasky Medical Center, 64239 Tel Aviv, Israel
zihum@tasmc.health. gov. il 1
Fowler VG Jr ,Boucher HW ,Corey GR , et al. Daptomycin versus standard therapy for bacteremia and endocarditis caused by Staphylococcus aureus. N Engl J Med 2006;355:653-665
Full Text | Web of Science | Medline2
Chang FY ,Peacock JE Jr ,Musher DM , et al. Staphylococcus aureus bacteremia: recurrence and the impact of antibiotic treatment in a prospective multicenter study. Medicine (Baltimore) 2003;82:333-339
CrossRef | Web of Science | Medline3
Siegman-Igra Y ,Reich P ,Orni-Wasserlauf R ,Schwartz D ,Giladi M . The role of vancomycin in the persistence or recurrence of Staphylococcus aureus bacteraemia. Scand J Infect Dis 2005;37:572-578
CrossRef | Web of Science | Medline
To the Editor:
Fowler et al. conclude that daptomycin therapy is not inferior to standard therapy for patients with S. aureus bacteremia and right-sided endocarditis. The two study groups were very heterogeneous: each included several types of infections involving a small number of patients (making it difficult to interpret the results) and strains with different degrees of susceptibility to methicillin. Vancomycin is associated with a slow clinical response,1 and as compared with antistaphylococcal penicillins,2 it has a lower rate of clinical efficacy for severe S. aureus infections. Thus, the comparison with daptomycin is distorted by the fact that the control group included infections caused by MSSA and infections caused by methicillin-resistant strains of S. aureus (MRSA), which were treated with therapies of different efficacy. However, the reported success rate associated with cloxacillin plus an aminoglycoside for uncomplicated right-sided endocarditis is excellent (94.4%).3 The success rates for the treatment of uncomplicated right-sided endocarditis in the study by Fowler et al. (50% among patients who received daptomycin vs. 25% among those who received standard therapy) are not acceptable, and could be explained by the small number of patients (six vs. four). Thus, the lack of statistical significance between these two subgroups should not be interpreted as indicating noninferiority between them.4
4 ReferencesManuel Torres-Tortosa, M.D.
Francisco J. Caballero-Granado, M.D.
Jesús Canueto, M.D.
Hospital Punta de Europa, 11207 Algeciras, Spain
mtt@comcadiz.com 1
Levine DP ,Fromm BS ,Reddy BR . Slow response to vancomycin or vancomycin plus rifampin in methicillin-resistant Staphylococcus aureus endocarditis. Ann Intern Med 1991;115:674-680
Web of Science | Medline2
Gonzalez C ,Rubio M ,Romero-Vivas J ,Gonzalez M ,Picazo JJ . Bacteremic pneumonia due to Staphylococcus aureus: a comparison of disease caused by methicillin-resistant and methicillin-susceptible organisms. Clin Infect Dis 1999;29:1171-1177
CrossRef | Web of Science | Medline3
Torres-Tortosa M ,de Cueto M ,Vergara A , et al. Prospective evaluation of a two-week course of intravenous antibiotics in intravenous drug addicts with infective endocarditis. Eur J Clin Microbiol Infect Dis 1994;13:559-564
CrossRef | Web of Science | Medline4
Altman DG ,Bland JM . Absence of evidence is not evidence of absence. BMJ 1995;311:485-485
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To the Editor:
With regard to the article by Moran et al. (Aug. 17 issue),1 it appears that MRSA abscesses will have to be treated as they were in the days before penicillin — that is, by means of incision and drainage. As any surgeon or emergency department doctor knows, the appropriate treatment for an abscess is incision and drainage. Add an antibiotic if you think the attendant cellulitis warrants it (although practically everyone will add an antibiotic, regardless).
1 ReferencesLynn Jetton, M.D.
1910 Cherokee Ave. SW, Cullman, AL 350551
Moran GJ ,Krishnadasan A ,Gorwitz RJ , et al. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med 2006;355:666-674
Full Text | Web of Science | Medline
Author/Editor Response
Siegman-Igra and Torres-Tortosa and colleagues inquired about the choice of standard therapies for this trial. We chose to use an antistaphylococcal penicillin or vancomycin to ensure that patients received the best and most appropriate therapy on the basis of the susceptibility of the infecting organism and the presence or absence of an allergy to penicillin. Ten patients in the study with MSSA bacteremia received vancomycin. Seven of these patients had documented penicillin allergies, and three patients did not. Of these 10 patients, 6 (60%), including 2 of the 3 who did not have a penicillin allergy, had a successful outcome 42 days after the end of therapy; the outcomes of 3 patients could not be evaluated because they withdrew consent, and therapy failed in 1 patient. One patient with MRSA infection inappropriately received an antistaphylococcal penicillin for 8 days. We have analyzed the data according to the pathogen-specific therapy — that is, according to whether patients received an antistaphylococcal penicillin for MSSA infection or vancomycin for MRSA infection (Table 1Table 1
Distribution of Successful Outcomes 42 Days after the End of Therapy.). The performance of daptomycin was similar to that of the standard therapies for both MSSA and MRSA infections in this analysis; however, the power to detect a difference in outcome is quite limited.Sara E. Cosgrove, M.D.
Johns Hopkins University School of Medicine, Baltimore, MD 21205Vance G. Fowler, Jr., M.D., M.H.S.
Duke University Medical Center, Durham, NC 27710
vance.fowler@duke. edu Helen W. Boucher, M.D.
Tufts–New England Medical Center, Boston, MA 02111Author/Editor Response
Jetton is correct that the primary treatment for a skin abscess is incision and drainage, as noted in our article. The additional benefit of antimicrobial therapy remains unclear. Previous investigations suggested similar cure rates with or without antibiotics, but these studies were performed before the emergence of community-associated MRSA and were limited by their use of nonrandomized designs, small numbers of subjects, vague definitions of outcomes, nonstandardized drainage, or antibiotics lacking appropriate activity.1-3 In one retrospective study of children, treatment failure with drainage alone was associated with an abscess size of 5 cm2 or larger.4 Inadequate drainage due to poor technique or misdiagnosis of the abscess as simple cellulitis can lead to treatment failure. Until we have better studies to clarify this issue, antimicrobial therapy known to be active against MRSA should be given to patients with systemic illness or clinically significant associated cellulitis, immunovascular or vascular compromise, an abscess in a high-risk location (e.g., a hand or the face), or a lack of a response to incision and drainage alone, and such antimicrobial therapy should be considered for recurrent infection.5
5 ReferencesGregory J. Moran, M.D.
David A. Talan, M.D.
Olive View–UCLA Medical Center, Sylmar, CA 91342
idnet@ucla.edu 1
Meislin HW ,Lerner SA ,Graves MH , et al. Cutaneous abscesses: anaerobic and aerobic bacteriology and outpatient management. Ann Intern Med 1977;87:145-149
Web of Science | Medline2
Llera JL ,Levy RC . Treatment of cutaneous abscess: a double-blind clinical study. Ann Emerg Med 1985;14:15-19
CrossRef | Web of Science | Medline3
Macfie J ,Harvey J . The treatment of acute superficial abscesses: a prospective clinical trial. Br J Surg 1977;64:264-266
CrossRef | Web of Science | Medline4
Lee MC ,Rios AM ,Aten MF , et al. Management and outcome of children with skin and soft tissue abscesses caused by community-acquired methicillin-resistant Staphylococcus aureus. Pediatr Infect Dis J 2004;23:123-127
CrossRef | Web of Science | Medline5
Gorwitz RJ, Jernigan DB, Powers JH, Jernigan JA, Participants in the CDC-Convened Experts' Meeting on Management of MRSA in the Community. Strategies for clinical management of MRSA in the community: summary of an experts' meeting convened by the Centers for Disease Control and Prevention. March 2006. (Accessed October 26, 2006, at http://www.cdc.gov/ncidod/dhqp/ar_mrsa_ca.html.)
- Citing Articles (1)
Citing Articles
1
Benito Almirante. (2008) Bacteriemia e infecciones endovasculares por grampositivos: nuevas opciones terapéuticas. Enfermedades Infecciosas y Microbiología Clínica 26, 44-52
CrossRef
