Retrospective Analysis of Risk Factors for Linezolid-associated Hyponatremia in Critical Patients

OBJECTIVE To examine the incidence rate of hyponatremia that developed during linezolid therapy and identify its risk factors. METHODS In this retrospective analysis study, 152 hospitalized patients treated with linezolid in intensive critical unit of Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University between January 2017 and July 2019 were analyzed. Hyponatremia was defined as sodium level ≤ 134 mmol·L^-1 for the duration of linezolid therapy. Its risk factors were identified via a Logistic regression analysis. RESULTS Hyponatremia occurred in 28(23.3%) patients, and among these it was severe in two cases (sodium level ≤ 128 mmol·L^-1). Univariate and multiple Logistic regression analyses identified the plasma C-reactive protein(CRP) level(b=0.010, OR=1.019, 95%CI 1.005-1.033, P=0.007) before the initial administration of linezolid and the concomitant use of a fat emulsion and amino acids(18) injection(β=-1.591, OR=0.151, 95%CI 0.034-0.673, P=0.002) as the independent variables associated with the development of hyponatremia, respectively. Before linezolid treatment, the CRP levels of the hyponatremia group were significantly higher than those of the no-hyponatremia group(t=-2.932, P=0.004). The frequency of hyponatremia development was significantly higher in the patients who received both the fat emulsion and amino acids(18) injection and linezolid (c²=20.444, P=0.003). CONCLUSION These results suggest that the plasma sodium levels of patients with severe inflammation who are treated with linezolid and those of linezolid-treated patients co-administered a fat emulsion and amino acids(18) injection shall be continuously monitored.