Trough-guided Versus AUC/MIC-Guided Vancomycin Monitoring: A Cost Analysis.

PURPOSE: Recent vancomycin dosing and monitoring guidelines recommend monitoring vancomycin area under the 24-hour time-concentration curve instead of traditional trough-only monitoring. This study aimed to compare the total costs of vancomycin dosing and monitoring between trough-guided and AUC-guided approaches in a quaternary hospital from Brazil. METHODS: In this retrospective cohort study, patients were divided into 2 groups according to the monitoring method. Patients with previous renal impairment were excluded. Vancomycin AUC was estimated by using 2 steady-state serum concentrations and first-order kinetics equations. The primary outcome was total cost of vancomycin therapy and monitoring from the hospital perspective, which included costs of cumulative doses, laboratory fees, materials used in blood collection, nursing time for collection, and pharmacist time for result interpretation. FINDINGS: A total of 68 patients were included in the AUC/MIC-guided monitoring group, and 76 patients were included in the trough-guided monitoring group. There were no significant differences between groups regarding baseline serum creatinine level, duration of vancomycin therapy, and cumulative vancomycin dose. The median (interquartile range) total vancomycin drug and monitoring cost was $298.32 ($153.81-$429.85) for the AUC/MIC-guided group compared with $285.59 ($198.81-$435.57) for the trough-guided group (P = 0.9658). IMPLICATIONS: Vancomycin AUC estimation using 2 steady-state serum concentrations and first-order kinetics equations is a feasible alternative for limited-resource institutions that intend to transition from a trough approach to AUC/MIC-guided monitoring.

Vancomycin area under the curve-guided monitoring in pediatric patients. / Monitoramento orientado pela área sob a curva da vancomicina em pacientes pediátricos.

OBJECTIVE: To assess the percentage of vancomycin area under the curve/minimum inhibitory concentration target attainment in pediatric patients after the empirical dose regimen and to demonstrate the applicability of this method for vancomycin monitoring. METHODS: A retrospective cohort study was performed including pediatric patients with normal renal function admitted between January 2020 and December 2020. The one-compartment model with first-order kinetics was used to estimate the pharmacokinetic parameters, and the area under the curve was calculated by the trapezoidal rule. The therapeutic target was defined as area under the curve/minimum inhibitory concentration ≥ 400 and < 600. The Chi-squared test was applied to compare the percentage of target attainment over age groups, while the pharmacokinetic parameters were compared by the Kruskal-Wallis test with Dunn's test for post hoc analyses. We considered significant p-values < 0.05. RESULTS: In total, 42 pairs of vancomycin levels were analyzed from 17 patients enrolled in this study. After empirical vancomycin daily dosing, the therapeutic target was achieved in five (29%) patients; four patients (24%) had a supratherapeutic initial area under the curve/minimum inhibitory concentration value (> 600mg.h/L), and eight (47%) patients had subtherapeutic values (< 400mg.h/L). The most identified pathogens were Staphylococcus spp. (n = 7). Trough levels and areas under the curve showed moderate correlation values (R2 = 0.73). Acute kidney injury occurred in one (6%) patient. CONCLUSION: Most patients did not reach the therapeutic target with a vancomycin empirical dose regimen, and the implementation of area under the curve-based dosing using two sample measurements allowed for real-time dose adjustments based on individuals' pharmacokinetic parameters.

OBJETIVO: Avaliar a probabilidade de atingir o alvo pela razão entre a área sob a curva e a concentração inibitória mínima de vancomicina em pacientes pediátricos após o esquema de dose empírica e demonstrar a aplicabilidade desse método para o monitoramento da vancomicina. METÓDOS: Foi realizado um estudo de coorte retrospectivo que incluiu pacientes pediátricos com função renal normal internados entre janeiro e dezembro de 2020. O modelo de um compartimento com cinética de primeira ordem foi utilizado para estimar os parâmetros farmacocinéticos, e a área sob a curva foi calculada pela regra do trapézio. O alvo terapêutico foi definido como a razão entre a área sob a curva e a concentração inibitória mínima ≥ 400 e < 600. O teste do qui-quadrado foi aplicado para comparar a probabilidade de atingir o alvo nos grupos etários, enquanto os parâmetros farmacocinéticos foram comparados pelo teste de Kruskal-Wallis com o teste de Dunn para análises post hoc. Consideraram-se significativos os valores de p < 0,05. RESULTADOS: Foram analisados, no total, 42 pares de níveis de vancomicina de 17 pacientes inscritos neste estudo. Após a dose diária empírica de vancomicina, o alvo terapêutico foi atingido em cinco (29%) pacientes; quatro pacientes (24%) apresentavam razão entre a área sob a curva inicial supraterapêutica e o valor de concentração inibitória mínima (> 600mg.h/L) e oito (47%) tinham valores subterapêuticos (< 400mg.h/L). Os patógenos mais identificados foram Staphylococcus spp. (n = 7). Os níveis de vale e as áreas sob a curva mostraram valores moderados de correlação (R2 = 0,73). Um (6%) paciente apresentou lesão renal aguda. CONCLUSÃO: A maioria dos pacientes não atingiu o alvo terapêutico com esquema de dose empírica de vancomicina, e a implementação de dosagem baseada na área sob a curva usando duas medições de amostra permitiu ajustes de dose em tempo real com base nos parâmetros farmacocinéticos dos indivíduos.

Monitoramento orientado pela área sob a curva da vancomicina em pacientes pediátricos / Vancomycin area under the curve-guided monitoring in pediatric patients

RESUMO Objetivo: Avaliar a probabilidade de atingir o alvo pela razão entre a área sob a curva e a concentração inibitória mínima de vancomicina em pacientes pediátricos após o esquema de dose empírica e demonstrar a aplicabilidade desse método para o monitoramento da vancomicina. Metódos: Foi realizado um estudo de coorte retrospectivo que incluiu pacientes pediátricos com função renal normal internados entre janeiro e dezembro de 2020. O modelo de um compartimento com cinética de primeira ordem foi utilizado para estimar os parâmetros farmacocinéticos, e a área sob a curva foi calculada pela regra do trapézio. O alvo terapêutico foi definido como a razão entre a área sob a curva e a concentração inibitória mínima ≥ 400 e < 600. O teste do qui-quadrado foi aplicado para comparar a probabilidade de atingir o alvo nos grupos etários, enquanto os parâmetros farmacocinéticos foram comparados pelo teste de Kruskal-Wallis com o teste de Dunn para análises post hoc. Consideraram-se significativos os valores de p < 0,05. Resultados: Foram analisados, no total, 42 pares de níveis de vancomicina de 17 pacientes inscritos neste estudo. Após a dose diária empírica de vancomicina, o alvo terapêutico foi atingido em cinco (29%) pacientes; quatro pacientes (24%) apresentavam razão entre a área sob a curva inicial supraterapêutica e o valor de concentração inibitória mínima (> 600mg.h/L) e oito (47%) tinham valores subterapêuticos (< 400mg.h/L). Os patógenos mais identificados foram Staphylococcus spp. (n = 7). Os níveis de vale e as áreas sob a curva mostraram valores moderados de correlação (R2 = 0,73). Um (6%) paciente apresentou lesão renal aguda. Conclusão: A maioria dos pacientes não atingiu o alvo terapêutico com esquema de dose empírica de vancomicina, e a implementação de dosagem baseada na área sob a curva usando duas medições de amostra permitiu ajustes de dose em tempo real com base nos parâmetros farmacocinéticos dos indivíduos.

ABSTRACT Objective: To assess the percentage of vancomycin area under the curve/minimum inhibitory concentration target attainment in pediatric patients after the empirical dose regimen and to demonstrate the applicability of this method for vancomycin monitoring. Methods: A retrospective cohort study was performed including pediatric patients with normal renal function admitted between January 2020 and December 2020. The one-compartment model with first-order kinetics was used to estimate the pharmacokinetic parameters, and the area under the curve was calculated by the trapezoidal rule. The therapeutic target was defined as area under the curve/minimum inhibitory concentration ≥ 400 and < 600. The Chi-squared test was applied to compare the percentage of target attainment over age groups, while the pharmacokinetic parameters were compared by the Kruskal-Wallis test with Dunn's test for post hoc analyses. We considered significant p-values < 0.05. Results: In total, 42 pairs of vancomycin levels were analyzed from 17 patients enrolled in this study. After empirical vancomycin daily dosing, the therapeutic target was achieved in five (29%) patients; four patients (24%) had a supratherapeutic initial area under the curve/minimum inhibitory concentration value (> 600mg.h/L), and eight (47%) patients had subtherapeutic values (< 400mg.h/L). The most identified pathogens were Staphylococcus spp. (n = 7). Trough levels and areas under the curve showed moderate correlation values (R2 = 0.73). Acute kidney injury occurred in one (6%) patient. Conclusion: Most patients did not reach the therapeutic target with a vancomycin empirical dose regimen, and the implementation of area under the curve-based dosing using two sample measurements allowed for real-time dose adjustments based on individuals' pharmacokinetic parameters.