A Comparison of Cefazolin Versus Ceftriaxone for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bacteremia in a Tertiary Care VA Medical Center

Abstract

BackgroundCefazolin and ceftriaxone are frequently used to treat methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, especially in the realm of outpatient parenteral antimicrobial therapy. Both antimicrobials have been associated with favorable clinical outcomes for mixed MSSA infections. However, limited published data exist specifically comparing the use of these agents for the treatment of MSSA bacteremia.MethodsWe conducted a retrospective cohort study of Veteran patients with MSSA bacteremia who received ≥14 days of cefazolin or ceftriaxone between 2009 and 2014. Rates of treatment failure were compared between both groups. Treatment failure was defined as therapy extension, incomplete therapy, unplanned oral suppressive therapy, relapse of infection, or hospital admission or surgery within 90 days.ResultsOut of 71 patients, 38 received treatment with cefazolin and 33 with ceftriaxone. The overall rate of treatment failure was 40.8%, with significantly more failures among patients receiving ceftriaxone (54.5% versus 28.9%; P = .029). Factors associated with treatment failure included longer duration of parenteral therapy, heart failure, and treatment in an external skilled nursing facility as compared with treatment in the Department of Veterans Affairs attached Community Living Center.ConclusionsCeftriaxone had a higher rate of treatment failure than cefazolin for the treatment of MSSA bacteremia in a Veteran population. Potential reasons for this could include the higher protein binding of ceftriaxone, ultimately resulting in lower serum concentrations of free drug, or other unknown factors. Further studies are warranted to confirm these results.

Ceftriaxone as an Alternative Therapy for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bacteremia after Initial Clearance of Bloodstream Infection

“…e primary composite outcome of clinical cure was achieved in 28 (65.1%) patients by day 7 of therapy (Table 3), with more patients achieving clinical cure in the SOCTgroup than the ceftriaxone group (78.3% vs 50%, P � 0.052). WBC count normalization within 7 days occurred in significantly more patients in the SOCT group than in the ceftriaxone group (87% vs 60%, P � 0.043); however, the time to WBC normalization was not significantly different between groups (3 [1][2][3][4][5][6] days SOCT vs 3.5 [1][2][3][4][5][6][7][8][9][10][11][12] Case Reports in Infectious Diseases [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] days and was not significantly different between groups.…”

“…ere were 5 (11.6%) patients who experienced a recurrent MSSA bacteremia within 60 days. e median time of follow-up post-discharge was 18 [13][14][15][16][17][18][19][20][21][22][23][24] days with patients in the SOCT group following up significantly sooner than the ceftriaxone group (12.5 [3.5-14] days vs 23 days, P � 0.003).…”

“…Few studies have evaluated ceftriaxone versus SOCT for MSSA bloodstream infections, and all have small sample sizes [ 17 , 22 ]. Despite this, we found comparable microbiological cure rates for both treatment arms (SOCT [91.3% vs 94.1%] and ceftriaxone [80% vs 95.2%]) and no differences between the groups in clinical cure rates [ 22 ].…”

“…Additionally, the majority of their patients received ceftriaxone in an ambulatory setting, whereas all of our patients were treated initially as inpatients, regardless of treatment group. Another evaluation of ceftriaxone for MSSA bloodstream infections ( n = 71) performed by Carr and colleagues also took place at a VA Medical Center and found similar failure rates [ 17 ]. However, in this study, failure was associated with ceftriaxone usage despite similar durations of bacteremia and days of empiric therapy to our study.…”

“…Ceftriaxone presents an attractive alternative to ASPs or cefazolin and can be dosed once daily. Few studies have investigated the use of ceftriaxone as an alternative to SOCT [ 15 – 17 ]. Additionally, ceftriaxone (2 g, daily) has a low AWP of $29 per day.…”