Impact of teicoplanin maintenance dose and MIC values on the clinical outcomes of patients treated for methicillin-resistant Staphylococcus aureus bacteremia

OBJECTIVES: Teicoplanin, a glycopeptide, is regarded as among the drug choices for methicillin-resistant Staphylococcus aureus (MRSA) infections. Few studies have evaluated the relationship between teicoplanin minimal inhibitory concentrations (MICs) and outcomes among patients with serious MRSA infections. SUBJECTS AND METHODS: We investigated the relationship between teicoplanin maintenance dose and clinical outcomes, on the completion of teicoplanin therapy, in bacteremia patients with MRSA infection, with different teicoplanin MICs. A total of 146 adult patients with MRSA bacteremia were enrolled at Kaohsiung Chang Gung Memorial Hospital between September 2012 and September 2015. RESULTS: A higher number of patients in the high-dose regimen group (6 mg/kg/12 h) had favorable outcomes than those in the standard-dose regimen group (6 mg/kg/24 h) (84.1% vs 41.2%; p<0.01), regardless of the teicoplanin MICs. In the multivariate analysis, a Pittsburgh bacteremia score ≥4 (OR, 0.07, 95% CI, 0.03–0.19) was a risk factor for an unfavorable final clinical response, whereas high-dose teicoplanin maintenance therapy for MRSA bacteremia was significantly associated with a favorable final response (OR, 25.3 [95% CI, 4.43–144.03] for isolates with a teicoplanin MIC ≥1.5 mg/L and OR, 5.6 [95% CI, 1.57–19.91] for isolates with a teicoplanin MIC <1.5 mg/L). Survival at 30 days was significantly better for patients receiving high-dose teicoplanin maintenance treatment, regardless of the teicoplanin MICs of the MRSA isolates. Patients were selected using propensity score matching, based on the independent predictors of a favorable final outcome. After appropriate propensity score matching, patients in the high-dose regimen group still had a statistically significant favorable outcome at the end of treatment (84.1% vs 40.9%; p<0.01). CONCLUSION: The results suggested that high-dose teicoplanin maintenance treatment is associated with more favorable outcomes than standard-dose teicoplanin maintenance treatment, for patients with MRSA bacteremia, regardless of the teicoplanin MIC.