Therapeutic Drug Monitoring and Impact Indicator of Vancomycin Pharmacokinetics in Abdominal Cancer Patients complicated with Severe Infectious Disease

Abstract Abstract Objective: This study was designed to investigate effectiveness of therapeutic drug monitoring (TDM) and impact indicator of vancomycin pharmacokinetics in abdominal cancer patients complicated with severe infectious disease. Methods: A total of 78 patients abdominal cancer patients complicated with severe infectious disease were included. Vancomycin serum trough concentrations were measured using the fluorescence polarization immunoassay (FPIA) method. The patients were divided into early and delayed groups based on whether they achieve the target concentration. And clinical factors were compared between two groups. Results: The average initial therapeutic dose of vancomycin was 15.18±3.29 mg/kg (q12h). Ultimately, we collected 78 patient‘s trough concentrations data. The research revealed that the abdominal cancer patients complicated with severe infectious disease had significantly lower initial vancomycin trough concentrations (median [IQR]: 6.90[5.28-11.20] mg/L) compared with the recommended standard goal vancomycin trough concentration (10-15 or 15-20 mg/L). Multiple regression analysis revealed that Cys-C was the most important variable for vancomycin target trough achievement. We divided patients into early and delayed groups based on whether the initial trough concentration achieved standard goal trough concentration. Although the clinical outcomes were similar between two groups, the duration of mechanical ventilation in Early group was considerably shorter compared with group Delayed group (χ2=4.532; p < 0.05; Fig 1E). Propensity score weighting further confirmed that the duration of mechanical ventilation (χ2=6.607; p < 0.05; Fig 1F) and vasoactive agent (χ2=6.106; p < 0.05; Fig 1D) was considerably shorter compared with group Delayed group. Conclusions: The steady-state initial vancomycin trough concentration was significantly reduced in abdominal cancer patients complicated with severe infectious disease. Higher initial dosage regimen is needed to ensure clinical effectiveness. The baseline Cys-C level measured prior to administration of vancomycin is suggested to be the most suitable parameter to predict whether vancomycin trough concentration is up to standard dosage. Early attainment of target concentration significantly improved hemodynamic stability and reduced duration of mechanical ventilation.