Factors Associated With Voriconazole Concentration in Pediatric Patients

Background: Serum concentrations of voriconazole are difficult to predict, especially in pediatric patients, because of its complex pharmacokinetic characteristics. This study aimed to identify the factors associated with the concentration of voriconazole in pediatric patients. Methods: This cohort study was based on retrospective data collection and involved the administration of voriconazole to pediatric patients younger than 18 years, between January 2010 and August 2017. Electronic medical records of the patients were reviewed to collect demographic characteristics, voriconazole treatment regimen, and factors that could potentially influence voriconazole trough concentrations. A voriconazole trough serum concentration of less than 1.0 mcg/mL or greater than 5.5 mcg/mL was defined as outside the therapeutic range and was set as the outcome of this study. Results: Among the 114 patients enrolled, 61 patients were included in the analysis. Oral administration of a maintenance dose of voriconazole and C-reactive protein (CRP) level were significantly and independently associated with a low initial trough concentration of voriconazole (<1.0 mcg/mL). Alanine aminotransferase levels were a significant factor associated with a high initial trough concentration of voriconazole (>5.5 mcg/mL) after adjusting for sex, age, weight, and serum creatinine (odds ratio 5.42; 95% confidence interval 1.34–21.97). Conclusions: Considering the variability of voriconazole concentrations in pediatric patients, monitoring certain parameters and considering the route of administration could help determine the therapeutic range of voriconazole and subsequently avoid unwanted effects.