Evaluation of vancomycin initial trough levels in children: A 1-year retrospective study

Background and objectives: Achieving vancomycin therapeutic levels is essential for antibacterial success and resistance prevention. Multiple studies have shown that most of the children fail to reach therapeutic trough levels (10–20 µg/mL). This study aims to determine the frequency of achieving therapeutic vancomycin initial trough levels in children, evaluate the effect of age on that achievement and the mean initial trough levels, and the frequency of supratherapeutic levels. Methods: Children aged 1 month to 12 years who received three or more vancomycin doses 15 mg/kg every 6 h while admitted at our hospital from February 2016 to January 2017, and had a level before the fourth dose were included. Cases with high baseline serum creatinine, acute kidney injury, and congenital heart disease were excluded. Results: Out of 75 included cases, one third, 28/75 (37.3%), achieved goal. The lowest frequency was 6/28 (21.4%) of the 2–5 years group, which were statistically less likely to achieve, and had significantly lower mean initial trough than the 1–23 months group ( P = 0.026 and 0.013, respectively). Mean initial trough levels were 10.1, 7.3, and 8.2 µg/mL in the 1–23 months, 2–5 years, and 6–12 years groups, respectively ( P = 0.014). No supratherapeutic levels were observed. Conclusion: Vancomycin dose of 60 mg/kg/day is insufficient to attain target levels for most of the children. Children aged 2–5 years are the least likely to achieve and have the lowest mean levels. More intensified doses are warranted to be studied prospectively to identify the most effective empiric dose for children.