Area under the concentration-time curve to minimum inhibitory concentration ratio as a predictor of vancomycin treatment outcome in methicillin-resistant Staphylococcus aureus bacteraemia

作者：Jung Younghee; Song Kyoung Ho^*; Cho Jeong eun; Kim Hyung sook; Kim Nak Hyun; Kim Taek Soo; Choe Pyoeng Gyun; Chung Jae Yong; Park Wan Beom; Bang Ji Hwan; Kim Eu Suk; Park Kyoung Un; Park Sang Won; Bin Kim Hong; Kim Nam Joong; Oh Myoung don

来源：International Journal of Antimicrobial Agents, 2014, 43(2): 179-183.

DOI：10.1016/j.ijantimicag.2013.10.017

• Vancomycin
• Methicillin-resistant Staphylococcus aureus
• Bacteraemia
• Area under the concentration-time curve
• Minimum inhibitory concentration

There have been few clinical studies on the association between the 24-h area under the concentration-time curve (AUC24) to minimum inhibitory concentration (MIC) ratio and vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus (MRSA) infections. Patients with MRSA bacteraemia between July 2009 and January 2012 were analysed retrospectively. All adult patients treated with vancomycin for = 72 h without dialysis were included. The MIC was determined by Etest and broth microdilution (BMD). Initial steady-state AUC24 was estimated using a Bayesian model, and the AUC24/MIC cut-off value for differentiating treatment success and failure was calculated by classification and regression tree (CART) analysis. In total, 76 patients were enrolled; vancomycin treatment failure occurred in 20 patients (26.3%). Catheter-related infection was the most frequent (35.5%), followed by surgical site infection (26.3%), whilst 25 (32.9%) had complicated infections. In univariate analysis, decreased MRSA vancomycin susceptibility (MIC = 1.5 mg/L) and vancomycin trough levels (15-20 mg/L) were not associated with treatment outcomes. In the CART analysis, low initial vancomycin AUC24/MIC (< 430 by Etest; < 398.5 by BMD) was associated with a higher treatment failure rate (50.0% vs. 25.0%, P = 0.039 by Etest; 45.0% vs. 23.2%; P = 0.065 by BMD). In multivariate analysis, low initial vancomycin AUC24/MIC was a significant risk factor for treatment failure [ adjusted odds ratio (aOR) = 4.39, 95% confidence interval (CI), 1.26-15.35 by Etest; aOR = 3.73, 95% CI 1.10-12.61 by BMD]. In MRSA bacteraemia, a low initial vancomycin AUC24/MIC is an independent risk factor for vancomycin treatment failure.

• 出版日期2014-2