Concordance of Vancomycin Population-Predicted Pharmacokinetics with Patient-Specific Pharmacokinetics in Adult Hospitalized Patients: A Case Series

摘要

BackgroundVancomycin empiric therapy is commonly dosed using clinical algorithms adapted from population-predicted pharmacokinetic parameters. However, precise dosing of vancomycin can be designed using patient-specific pharmacokinetic calculations.ObjectiveThe objective of this study is to assess the correlational fit between vancomycin population-predicted and patient-specific pharmacokinetic parameters [elimination rate constant ( K sube/sub) and half-life ( t sub1/2/sub)] in a case series of adult hospitalized patients.MethodsThis is a single-center case series of hospitalized adult patients who received vancomycin, had creatinine clearance calculation for derivation of population-predicted pharmacokinetic parameters, and had two vancomycin concentrations for calculation of patient-specific pharmacokinetic parameters. The primary objective of this case series is to evaluate the correlation between population-predicted and patient-specific pharmacokinetic parameters. The secondary objectives of this study are to evaluate the mean bias and precision between the population-predicted and patient-specific pharmacokinetic parameters and to assess the correlation between population-predicted and patient-specific pharmacokinetic parameters in special population subgroups (obese patients with body mass index?≥?30?kg/msup2/sup and patients with renal dysfunction). All correlation analyses were performed on the population-predicted pharmacokinetics using diverse methods of estimating renal function (Salazar–Corcoran and Cockcroft–Gault methods using either ideal, actual, or adjusted body weights). All significance testing was set at an α of??0.05. IBM SPSS Statistics version 25 and SAS version 9.4 were used to conduct all statistical analyses.ResultsA total of 30 patients were included in the study; 33.3% (10/30) of the patients were obese and 56.7% (17/30) had renal dysfunction. In all patients in the study, the calculated population-predicted K sube/sub and t sub1/2/sub using all four creatinine clearance estimation methods were each significantly correlated with patient-specific K sube/sub and t sub1/2/sub (all Pearson correlation coefficients [ r ]:??+?0.7, p ?0.001). The population-predicted K sube/sub and t sub1/2/sub calculated using Cockcroft–Gault creatinine clearance using adjusted body weight showed the strongest association with patient-specific K sube/sub and t sub1/2/sub. In the subgroup analyses, all the population-predicted K sube/sub and t sub1/2/sub using four creatinine clearance estimation methods were each significantly correlated with patient-specific K sube/sub and t sub1/2/sub. The exception was the population-predicted t sub1/2/sub derived from Cockcroft–Gault creatinine clearance using actual body weight that did not show a significant correlation with patient-specific t sub1/2/sub in obese patients.ConclusionsIn this case series, population-predicted pharmacokinetic parameters were strongly correlated with patient-specific pharmacokinetic parameters. The vancomycin population-predicted pharmacokinetic formula can be used safely to predict a patient’s vancomycin pharmacokinetic disposition and can be maintained as an empiric dosing strategy in various hospitalized adult patients.