P-1298. A Comparison of Daptomycin and Linezolid in Treating Intraabdominal Infections Complicated by VRE Bacteremia

TL;DR

This study compares daptomycin and linezolid for treating intraabdominal infections caused by vancomycin-resistant Enterococci bloodstream infections, finding that high-dose daptomycin may improve survival.

Contribution

The study evaluates clinical efficacy of daptomycin versus linezolid in VRE-IAIs with BSI, highlighting high-dose daptomycin's potential mortality benefit.

Findings

Daptomycin was not associated with increased mortality compared to linezolid.

High-dose daptomycin (≥11 mg/kg) was linked to reduced mortality.

Mortality predictors included higher Pitt Bacteremia Score, lower platelet count, and malignancy.

Abstract

Vancomycin-resistant Enterococci (VRE) are pathogenic in intraabdominal infections (IAIs). While daptomycin (8–12 mg/kg) is effective for VRE bloodstream infections (BSIs), evidence supporting its use in VRE-IAIs remains limited. This study aims to evaluate the clinical efficacy of daptomycin versus linezolid in treating VRE-IAIs with BSI.Table 1The baseline characteristics of the patients in the daptomycin group and the linezolid group.Figure 1The mortality rate of patients with (a) BTI without peritonitis and liver abscesses (n=96) and with (b) peritonitis and intraabdominal abscesses (n=88), separated by the usage of linezolid, high-dose daptomycin, and low-dose daptomycin.

The baseline characteristics of the patients in the daptomycin group and the linezolid group.

The mortality rate of patients with (a) BTI without peritonitis and liver abscesses (n=96) and with (b) peritonitis and intraabdominal abscesses (n=88), separated by the usage of linezolid, high-dose daptomycin, and low-dose daptomycin.

We conducted a multicenter observational study. From April 2010 to October 2024, VRE-BSI patients with IAIs as the infection source treated with daptomycin or linezolid were included. The primary outcome was the 28-day in-hospital mortality.

Figure 2.The Kaplan–Meier curve of patients received linezolid, high-dose daptomycin (≥11 mg/kg), and low-dose daptomycin (<11 mg/kg).

The Kaplan–Meier curve of patients received linezolid, high-dose daptomycin (≥11 mg/kg), and low-dose daptomycin (<11 mg/kg).

Of 184 patients included, 149 received daptomycin and 35 received linezolid (Table 1). Most patients (98.3%) underwent source control procedures. The 28-day mortality did not differ significantly between daptomycin and linezolid groups (29.5% vs. 37.1%; P=0.38). The infection types included biliary tract infections (BTIs) in 75 patients (40.8%), peritonitis in 74 (40.2%), liver abscesses or infected cysts in 21 (11.4%), and intraabdominal abscesses in 14 (7.6%). Multivariable logistic regression identified the independent predictors of mortality including higher Pitt Bacteremia Score (adjusted odds ratio [aOR], 1.22; 95% confidence interval [CI], 1.06–1.41; P=0.006), lower platelet count (aOR, 0.996; 95% CI, 0.99–1.00; P=0.023), and malignancy (aOR, 2.41; 95% CI, 1.10–5.25; P=0.0027). Daptomycin was not associated with increased mortality versus linezolid (aOR, 0.63; 95% CI, 0.28–1.44; P=0.27). However, high-dose daptomycin (≥11 mg/kg) was linked to reduced mortality (aOR, 0.29; 95% CI, 0.09–0.91; P=0.03), whereas low-dose daptomycin showed no significant difference (aOR, 0.79; 95% CI, 0.34–1.85; P=0.59). Regimen changes due to adverse events were similar between the high- and low-dose daptomycin groups (1.89% vs. 2.44%; P=0.99). Mortality by infection types and survival curves are shown in Figures 1 and 2.

Daptomycin appears to be at least as effective as linezolid for the treatment of VRE-IAIs with BSI. Moreover, High-dose daptomycin (≥11 mg/kg) was related to improved survival. Further studies in VRE-IAIs without concurrent BSI are needed to clarify daptomycin’s effectiveness.

All Authors: No reported disclosures

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